adding ffmpeg specific version

1 files changed, 1358 insertions, 0 deletions

diff --git a/ffmpeg1/libavcodec/flacenc.c b/ffmpeg1/libavcodec/flacenc.c
new file mode 100644
index 0000000..dc932c6
--- /dev/null
+++ b/ffmpeg1/libavcodec/flacenc.c
@@ -0,0 +1,1358 @@
+/*
+ * FLAC audio encoder
+ * Copyright (c) 2006  Justin Ruggles <justin.ruggles@gmail.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/avassert.h"
+#include "libavutil/crc.h"
+#include "libavutil/intmath.h"
+#include "libavutil/md5.h"
+#include "libavutil/opt.h"
+#include "avcodec.h"
+#include "dsputil.h"
+#include "put_bits.h"
+#include "golomb.h"
+#include "internal.h"
+#include "lpc.h"
+#include "flac.h"
+#include "flacdata.h"
+#include "flacdsp.h"
+
+#define FLAC_SUBFRAME_CONSTANT  0
+#define FLAC_SUBFRAME_VERBATIM  1
+#define FLAC_SUBFRAME_FIXED     8
+#define FLAC_SUBFRAME_LPC      32
+
+#define MAX_FIXED_ORDER     4
+#define MAX_PARTITION_ORDER 8
+#define MAX_PARTITIONS     (1 << MAX_PARTITION_ORDER)
+#define MAX_LPC_PRECISION  15
+#define MAX_LPC_SHIFT      15
+
+enum CodingMode {
+    CODING_MODE_RICE  = 4,
+    CODING_MODE_RICE2 = 5,
+};
+
+typedef struct CompressionOptions {
+    int compression_level;
+    int block_time_ms;
+    enum FFLPCType lpc_type;
+    int lpc_passes;
+    int lpc_coeff_precision;
+    int min_prediction_order;
+    int max_prediction_order;
+    int prediction_order_method;
+    int min_partition_order;
+    int max_partition_order;
+    int ch_mode;
+} CompressionOptions;
+
+typedef struct RiceContext {
+    enum CodingMode coding_mode;
+    int porder;
+    int params[MAX_PARTITIONS];
+} RiceContext;
+
+typedef struct FlacSubframe {
+    int type;
+    int type_code;
+    int obits;
+    int wasted;
+    int order;
+    int32_t coefs[MAX_LPC_ORDER];
+    int shift;
+    RiceContext rc;
+    int32_t samples[FLAC_MAX_BLOCKSIZE];
+    int32_t residual[FLAC_MAX_BLOCKSIZE+1];
+} FlacSubframe;
+
+typedef struct FlacFrame {
+    FlacSubframe subframes[FLAC_MAX_CHANNELS];
+    int blocksize;
+    int bs_code[2];
+    uint8_t crc8;
+    int ch_mode;
+    int verbatim_only;
+} FlacFrame;
+
+typedef struct FlacEncodeContext {
+    AVClass *class;
+    PutBitContext pb;
+    int channels;
+    int samplerate;
+    int sr_code[2];
+    int bps_code;
+    int max_blocksize;
+    int min_framesize;
+    int max_framesize;
+    int max_encoded_framesize;
+    uint32_t frame_count;
+    uint64_t sample_count;
+    uint8_t md5sum[16];
+    FlacFrame frame;
+    CompressionOptions options;
+    AVCodecContext *avctx;
+    LPCContext lpc_ctx;
+    struct AVMD5 *md5ctx;
+    uint8_t *md5_buffer;
+    unsigned int md5_buffer_size;
+    DSPContext dsp;
+    FLACDSPContext flac_dsp;
+} FlacEncodeContext;
+
+
+/**
+ * Write streaminfo metadata block to byte array.
+ */
+static void write_streaminfo(FlacEncodeContext *s, uint8_t *header)
+{
+    PutBitContext pb;
+
+    memset(header, 0, FLAC_STREAMINFO_SIZE);
+    init_put_bits(&pb, header, FLAC_STREAMINFO_SIZE);
+
+    /* streaminfo metadata block */
+    put_bits(&pb, 16, s->max_blocksize);
+    put_bits(&pb, 16, s->max_blocksize);
+    put_bits(&pb, 24, s->min_framesize);
+    put_bits(&pb, 24, s->max_framesize);
+    put_bits(&pb, 20, s->samplerate);
+    put_bits(&pb, 3, s->channels-1);
+    put_bits(&pb,  5, s->avctx->bits_per_raw_sample - 1);
+    /* write 36-bit sample count in 2 put_bits() calls */
+    put_bits(&pb, 24, (s->sample_count & 0xFFFFFF000LL) >> 12);
+    put_bits(&pb, 12,  s->sample_count & 0x000000FFFLL);
+    flush_put_bits(&pb);
+    memcpy(&header[18], s->md5sum, 16);
+}
+
+
+/**
+ * Set blocksize based on samplerate.
+ * Choose the closest predefined blocksize >= BLOCK_TIME_MS milliseconds.
+ */
+static int select_blocksize(int samplerate, int block_time_ms)
+{
+    int i;
+    int target;
+    int blocksize;
+
+    av_assert0(samplerate > 0);
+    blocksize = ff_flac_blocksize_table[1];
+    target    = (samplerate * block_time_ms) / 1000;
+    for (i = 0; i < 16; i++) {
+        if (target >= ff_flac_blocksize_table[i] &&
+            ff_flac_blocksize_table[i] > blocksize) {
+            blocksize = ff_flac_blocksize_table[i];
+        }
+    }
+    return blocksize;
+}
+
+
+static av_cold void dprint_compression_options(FlacEncodeContext *s)
+{
+    AVCodecContext     *avctx = s->avctx;
+    CompressionOptions *opt   = &s->options;
+
+    av_log(avctx, AV_LOG_DEBUG, " compression: %d\n", opt->compression_level);
+
+    switch (opt->lpc_type) {
+    case FF_LPC_TYPE_NONE:
+        av_log(avctx, AV_LOG_DEBUG, " lpc type: None\n");
+        break;
+    case FF_LPC_TYPE_FIXED:
+        av_log(avctx, AV_LOG_DEBUG, " lpc type: Fixed pre-defined coefficients\n");
+        break;
+    case FF_LPC_TYPE_LEVINSON:
+        av_log(avctx, AV_LOG_DEBUG, " lpc type: Levinson-Durbin recursion with Welch window\n");
+        break;
+    case FF_LPC_TYPE_CHOLESKY:
+        av_log(avctx, AV_LOG_DEBUG, " lpc type: Cholesky factorization, %d pass%s\n",
+               opt->lpc_passes, opt->lpc_passes == 1 ? "" : "es");
+        break;
+    }
+
+    av_log(avctx, AV_LOG_DEBUG, " prediction order: %d, %d\n",
+           opt->min_prediction_order, opt->max_prediction_order);
+
+    switch (opt->prediction_order_method) {
+    case ORDER_METHOD_EST:
+        av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "estimate");
+        break;
+    case ORDER_METHOD_2LEVEL:
+        av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "2-level");
+        break;
+    case ORDER_METHOD_4LEVEL:
+        av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "4-level");
+        break;
+    case ORDER_METHOD_8LEVEL:
+        av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "8-level");
+        break;
+    case ORDER_METHOD_SEARCH:
+        av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "full search");
+        break;
+    case ORDER_METHOD_LOG:
+        av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "log search");
+        break;
+    }
+
+
+    av_log(avctx, AV_LOG_DEBUG, " partition order: %d, %d\n",
+           opt->min_partition_order, opt->max_partition_order);
+
+    av_log(avctx, AV_LOG_DEBUG, " block size: %d\n", avctx->frame_size);
+
+    av_log(avctx, AV_LOG_DEBUG, " lpc precision: %d\n",
+           opt->lpc_coeff_precision);
+}
+
+
+static av_cold int flac_encode_init(AVCodecContext *avctx)
+{
+    int freq = avctx->sample_rate;
+    int channels = avctx->channels;
+    FlacEncodeContext *s = avctx->priv_data;
+    int i, level, ret;
+    uint8_t *streaminfo;
+
+    s->avctx = avctx;
+
+    switch (avctx->sample_fmt) {
+    case AV_SAMPLE_FMT_S16:
+        avctx->bits_per_raw_sample = 16;
+        s->bps_code                = 4;
+        break;
+    case AV_SAMPLE_FMT_S32:
+        if (avctx->bits_per_raw_sample != 24)
+            av_log(avctx, AV_LOG_WARNING, "encoding as 24 bits-per-sample\n");
+        avctx->bits_per_raw_sample = 24;
+        s->bps_code                = 6;
+        break;
+    }
+
+    if (channels < 1 || channels > FLAC_MAX_CHANNELS) {
+        av_log(avctx, AV_LOG_ERROR, "%d channels not supported (max %d)\n",
+               channels, FLAC_MAX_CHANNELS);
+        return AVERROR(EINVAL);
+    }
+    s->channels = channels;
+
+    /* find samplerate in table */
+    if (freq < 1)
+        return -1;
+    for (i = 4; i < 12; i++) {
+        if (freq == ff_flac_sample_rate_table[i]) {
+            s->samplerate = ff_flac_sample_rate_table[i];
+            s->sr_code[0] = i;
+            s->sr_code[1] = 0;
+            break;
+        }
+    }
+    /* if not in table, samplerate is non-standard */
+    if (i == 12) {
+        if (freq % 1000 == 0 && freq < 255000) {
+            s->sr_code[0] = 12;
+            s->sr_code[1] = freq / 1000;
+        } else if (freq % 10 == 0 && freq < 655350) {
+            s->sr_code[0] = 14;
+            s->sr_code[1] = freq / 10;
+        } else if (freq < 65535) {
+            s->sr_code[0] = 13;
+            s->sr_code[1] = freq;
+        } else {
+            av_log(avctx, AV_LOG_ERROR, "%d Hz not supported\n", freq);
+            return AVERROR(EINVAL);
+        }
+        s->samplerate = freq;
+    }
+
+    /* set compression option defaults based on avctx->compression_level */
+    if (avctx->compression_level < 0)
+        s->options.compression_level = 5;
+    else
+        s->options.compression_level = avctx->compression_level;
+
+    level = s->options.compression_level;
+    if (level > 12) {
+        av_log(avctx, AV_LOG_ERROR, "invalid compression level: %d\n",
+               s->options.compression_level);
+        return AVERROR(EINVAL);
+    }
+
+    s->options.block_time_ms = ((int[]){ 27, 27, 27,105,105,105,105,105,105,105,105,105,105})[level];
+
+    if (s->options.lpc_type == FF_LPC_TYPE_DEFAULT)
+        s->options.lpc_type  = ((int[]){ FF_LPC_TYPE_FIXED,    FF_LPC_TYPE_FIXED,    FF_LPC_TYPE_FIXED,
+                                         FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON,
+                                         FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON,
+                                         FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON, FF_LPC_TYPE_LEVINSON,
+                                         FF_LPC_TYPE_LEVINSON})[level];
+
+    s->options.min_prediction_order = ((int[]){  2,  0,  0,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1})[level];
+    s->options.max_prediction_order = ((int[]){  3,  4,  4,  6,  8,  8,  8,  8, 12, 12, 12, 32, 32})[level];
+
+    if (s->options.prediction_order_method < 0)
+        s->options.prediction_order_method = ((int[]){ ORDER_METHOD_EST,    ORDER_METHOD_EST,    ORDER_METHOD_EST,
+                                                       ORDER_METHOD_EST,    ORDER_METHOD_EST,    ORDER_METHOD_EST,
+                                                       ORDER_METHOD_4LEVEL, ORDER_METHOD_LOG,    ORDER_METHOD_4LEVEL,
+                                                       ORDER_METHOD_LOG,    ORDER_METHOD_SEARCH, ORDER_METHOD_LOG,
+                                                       ORDER_METHOD_SEARCH})[level];
+
+    if (s->options.min_partition_order > s->options.max_partition_order) {
+        av_log(avctx, AV_LOG_ERROR, "invalid partition orders: min=%d max=%d\n",
+               s->options.min_partition_order, s->options.max_partition_order);
+        return AVERROR(EINVAL);
+    }
+    if (s->options.min_partition_order < 0)
+        s->options.min_partition_order = ((int[]){  2,  2,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0})[level];
+    if (s->options.max_partition_order < 0)
+        s->options.max_partition_order = ((int[]){  2,  2,  3,  3,  3,  8,  8,  8,  8,  8,  8,  8,  8})[level];
+
+    if (s->options.lpc_type == FF_LPC_TYPE_NONE) {
+        s->options.min_prediction_order = 0;
+    } else if (avctx->min_prediction_order >= 0) {
+        if (s->options.lpc_type == FF_LPC_TYPE_FIXED) {
+            if (avctx->min_prediction_order > MAX_FIXED_ORDER) {
+                av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n",
+                       avctx->min_prediction_order);
+                return AVERROR(EINVAL);
+            }
+        } else if (avctx->min_prediction_order < MIN_LPC_ORDER ||
+                   avctx->min_prediction_order > MAX_LPC_ORDER) {
+            av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n",
+                   avctx->min_prediction_order);
+            return AVERROR(EINVAL);
+        }
+        s->options.min_prediction_order = avctx->min_prediction_order;
+    }
+    if (s->options.lpc_type == FF_LPC_TYPE_NONE) {
+        s->options.max_prediction_order = 0;
+    } else if (avctx->max_prediction_order >= 0) {
+        if (s->options.lpc_type == FF_LPC_TYPE_FIXED) {
+            if (avctx->max_prediction_order > MAX_FIXED_ORDER) {
+                av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n",
+                       avctx->max_prediction_order);
+                return AVERROR(EINVAL);
+            }
+        } else if (avctx->max_prediction_order < MIN_LPC_ORDER ||
+                   avctx->max_prediction_order > MAX_LPC_ORDER) {
+            av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n",
+                   avctx->max_prediction_order);
+            return AVERROR(EINVAL);
+        }
+        s->options.max_prediction_order = avctx->max_prediction_order;
+    }
+    if (s->options.max_prediction_order < s->options.min_prediction_order) {
+        av_log(avctx, AV_LOG_ERROR, "invalid prediction orders: min=%d max=%d\n",
+               s->options.min_prediction_order, s->options.max_prediction_order);
+        return AVERROR(EINVAL);
+    }
+
+    if (avctx->frame_size > 0) {
+        if (avctx->frame_size < FLAC_MIN_BLOCKSIZE ||
+                avctx->frame_size > FLAC_MAX_BLOCKSIZE) {
+            av_log(avctx, AV_LOG_ERROR, "invalid block size: %d\n",
+                   avctx->frame_size);
+            return AVERROR(EINVAL);
+        }
+    } else {
+        s->avctx->frame_size = select_blocksize(s->samplerate, s->options.block_time_ms);
+    }
+    s->max_blocksize = s->avctx->frame_size;
+
+    /* set maximum encoded frame size in verbatim mode */
+    s->max_framesize = ff_flac_get_max_frame_size(s->avctx->frame_size,
+                                                  s->channels,
+                                                  s->avctx->bits_per_raw_sample);
+
+    /* initialize MD5 context */
+    s->md5ctx = av_md5_alloc();
+    if (!s->md5ctx)
+        return AVERROR(ENOMEM);
+    av_md5_init(s->md5ctx);
+
+    streaminfo = av_malloc(FLAC_STREAMINFO_SIZE);
+    if (!streaminfo)
+        return AVERROR(ENOMEM);
+    write_streaminfo(s, streaminfo);
+    avctx->extradata = streaminfo;
+    avctx->extradata_size = FLAC_STREAMINFO_SIZE;
+
+    s->frame_count   = 0;
+    s->min_framesize = s->max_framesize;
+
+    if (channels == 3 &&
+            avctx->channel_layout != (AV_CH_LAYOUT_STEREO|AV_CH_FRONT_CENTER) ||
+        channels == 4 &&
+            avctx->channel_layout != AV_CH_LAYOUT_2_2 &&
+            avctx->channel_layout != AV_CH_LAYOUT_QUAD ||
+        channels == 5 &&
+            avctx->channel_layout != AV_CH_LAYOUT_5POINT0 &&
+            avctx->channel_layout != AV_CH_LAYOUT_5POINT0_BACK ||
+        channels == 6 &&
+            avctx->channel_layout != AV_CH_LAYOUT_5POINT1 &&
+            avctx->channel_layout != AV_CH_LAYOUT_5POINT1_BACK) {
+        if (avctx->channel_layout) {
+            av_log(avctx, AV_LOG_ERROR, "Channel layout not supported by Flac, "
+                                             "output stream will have incorrect "
+                                             "channel layout.\n");
+        } else {
+            av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The encoder "
+                                               "will use Flac channel layout for "
+                                               "%d channels.\n", channels);
+        }
+    }
+
+    ret = ff_lpc_init(&s->lpc_ctx, avctx->frame_size,
+                      s->options.max_prediction_order, FF_LPC_TYPE_LEVINSON);
+
+    ff_dsputil_init(&s->dsp, avctx);
+    ff_flacdsp_init(&s->flac_dsp, avctx->sample_fmt,
+                    avctx->bits_per_raw_sample);
+
+    dprint_compression_options(s);
+
+    return ret;
+}
+
+
+static void init_frame(FlacEncodeContext *s, int nb_samples)
+{
+    int i, ch;
+    FlacFrame *frame;
+
+    frame = &s->frame;
+
+    for (i = 0; i < 16; i++) {
+        if (nb_samples == ff_flac_blocksize_table[i]) {
+            frame->blocksize  = ff_flac_blocksize_table[i];
+            frame->bs_code[0] = i;
+            frame->bs_code[1] = 0;
+            break;
+        }
+    }
+    if (i == 16) {
+        frame->blocksize = nb_samples;
+        if (frame->blocksize <= 256) {
+            frame->bs_code[0] = 6;
+            frame->bs_code[1] = frame->blocksize-1;
+        } else {
+            frame->bs_code[0] = 7;
+            frame->bs_code[1] = frame->blocksize-1;
+        }
+    }
+
+    for (ch = 0; ch < s->channels; ch++) {
+        FlacSubframe *sub = &frame->subframes[ch];
+
+        sub->wasted = 0;
+        sub->obits  = s->avctx->bits_per_raw_sample;
+
+        if (sub->obits > 16)
+            sub->rc.coding_mode = CODING_MODE_RICE2;
+        else
+            sub->rc.coding_mode = CODING_MODE_RICE;
+    }
+
+    frame->verbatim_only = 0;
+}
+
+
+/**
+ * Copy channel-interleaved input samples into separate subframes.
+ */
+static void copy_samples(FlacEncodeContext *s, const void *samples)
+{
+    int i, j, ch;
+    FlacFrame *frame;
+    int shift = av_get_bytes_per_sample(s->avctx->sample_fmt) * 8 -
+                s->avctx->bits_per_raw_sample;
+
+#define COPY_SAMPLES(bits) do {                                     \
+    const int ## bits ## _t *samples0 = samples;                    \
+    frame = &s->frame;                                              \
+    for (i = 0, j = 0; i < frame->blocksize; i++)                   \
+        for (ch = 0; ch < s->channels; ch++, j++)                   \
+            frame->subframes[ch].samples[i] = samples0[j] >> shift; \
+} while (0)
+
+    if (s->avctx->sample_fmt == AV_SAMPLE_FMT_S16)
+        COPY_SAMPLES(16);
+    else
+        COPY_SAMPLES(32);
+}
+
+
+static uint64_t rice_count_exact(int32_t *res, int n, int k)
+{
+    int i;
+    uint64_t count = 0;
+
+    for (i = 0; i < n; i++) {
+        int32_t v = -2 * res[i] - 1;
+        v ^= v >> 31;
+        count += (v >> k) + 1 + k;
+    }
+    return count;
+}
+
+
+static uint64_t subframe_count_exact(FlacEncodeContext *s, FlacSubframe *sub,
+                                     int pred_order)
+{
+    int p, porder, psize;
+    int i, part_end;
+    uint64_t count = 0;
+
+    /* subframe header */
+    count += 8;
+
+    /* subframe */
+    if (sub->type == FLAC_SUBFRAME_CONSTANT) {
+        count += sub->obits;
+    } else if (sub->type == FLAC_SUBFRAME_VERBATIM) {
+        count += s->frame.blocksize * sub->obits;
+    } else {
+        /* warm-up samples */
+        count += pred_order * sub->obits;
+
+        /* LPC coefficients */
+        if (sub->type == FLAC_SUBFRAME_LPC)
+            count += 4 + 5 + pred_order * s->options.lpc_coeff_precision;
+
+        /* rice-encoded block */
+        count += 2;
+
+        /* partition order */
+        porder = sub->rc.porder;
+        psize  = s->frame.blocksize >> porder;
+        count += 4;
+
+        /* residual */
+        i        = pred_order;
+        part_end = psize;
+        for (p = 0; p < 1 << porder; p++) {
+            int k = sub->rc.params[p];
+            count += sub->rc.coding_mode;
+            count += rice_count_exact(&sub->residual[i], part_end - i, k);
+            i = part_end;
+            part_end = FFMIN(s->frame.blocksize, part_end + psize);
+        }
+    }
+
+    return count;
+}
+
+
+#define rice_encode_count(sum, n, k) (((n)*((k)+1))+((sum-(n>>1))>>(k)))
+
+/**
+ * Solve for d/dk(rice_encode_count) = n-((sum-(n>>1))>>(k+1)) = 0.
+ */
+static int find_optimal_param(uint64_t sum, int n, int max_param)
+{
+    int k;
+    uint64_t sum2;
+
+    if (sum <= n >> 1)
+        return 0;
+    sum2 = sum - (n >> 1);
+    k    = av_log2(av_clipl_int32(sum2 / n));
+    return FFMIN(k, max_param);
+}
+
+
+static uint64_t calc_optimal_rice_params(RiceContext *rc, int porder,
+                                         uint64_t *sums, int n, int pred_order)
+{
+    int i;
+    int k, cnt, part, max_param;
+    uint64_t all_bits;
+
+    max_param = (1 << rc->coding_mode) - 2;
+
+    part     = (1 << porder);
+    all_bits = 4 * part;
+
+    cnt = (n >> porder) - pred_order;
+    for (i = 0; i < part; i++) {
+        k = find_optimal_param(sums[i], cnt, max_param);
+        rc->params[i] = k;
+        all_bits += rice_encode_count(sums[i], cnt, k);
+        cnt = n >> porder;
+    }
+
+    rc->porder = porder;
+
+    return all_bits;
+}
+
+
+static void calc_sums(int pmin, int pmax, uint32_t *data, int n, int pred_order,
+                      uint64_t sums[][MAX_PARTITIONS])
+{
+    int i, j;
+    int parts;
+    uint32_t *res, *res_end;
+
+    /* sums for highest level */
+    parts   = (1 << pmax);
+    res     = &data[pred_order];
+    res_end = &data[n >> pmax];
+    for (i = 0; i < parts; i++) {
+        uint64_t sum = 0;
+        while (res < res_end)
+            sum += *(res++);
+        sums[pmax][i] = sum;
+        res_end += n >> pmax;
+    }
+    /* sums for lower levels */
+    for (i = pmax - 1; i >= pmin; i--) {
+        parts = (1 << i);
+        for (j = 0; j < parts; j++)
+            sums[i][j] = sums[i+1][2*j] + sums[i+1][2*j+1];
+    }
+}
+
+
+static uint64_t calc_rice_params(RiceContext *rc, int pmin, int pmax,
+                                 int32_t *data, int n, int pred_order)
+{
+    int i;
+    uint64_t bits[MAX_PARTITION_ORDER+1];
+    int opt_porder;
+    RiceContext tmp_rc;
+    uint32_t *udata;
+    uint64_t sums[MAX_PARTITION_ORDER+1][MAX_PARTITIONS];
+
+    av_assert1(pmin >= 0 && pmin <= MAX_PARTITION_ORDER);
+    av_assert1(pmax >= 0 && pmax <= MAX_PARTITION_ORDER);
+    av_assert1(pmin <= pmax);
+
+    tmp_rc.coding_mode = rc->coding_mode;
+
+    udata = av_malloc(n * sizeof(uint32_t));
+    for (i = 0; i < n; i++)
+        udata[i] = (2*data[i]) ^ (data[i]>>31);
+
+    calc_sums(pmin, pmax, udata, n, pred_order, sums);
+
+    opt_porder = pmin;
+    bits[pmin] = UINT32_MAX;
+    for (i = pmin; i <= pmax; i++) {
+        bits[i] = calc_optimal_rice_params(&tmp_rc, i, sums[i], n, pred_order);
+        if (bits[i] <= bits[opt_porder]) {
+            opt_porder = i;
+            *rc = tmp_rc;
+        }
+    }
+
+    av_freep(&udata);
+    return bits[opt_porder];
+}
+
+
+static int get_max_p_order(int max_porder, int n, int order)
+{
+    int porder = FFMIN(max_porder, av_log2(n^(n-1)));
+    if (order > 0)
+        porder = FFMIN(porder, av_log2(n/order));
+    return porder;
+}
+
+
+static uint64_t find_subframe_rice_params(FlacEncodeContext *s,
+                                          FlacSubframe *sub, int pred_order)
+{
+    int pmin = get_max_p_order(s->options.min_partition_order,
+                               s->frame.blocksize, pred_order);
+    int pmax = get_max_p_order(s->options.max_partition_order,
+                               s->frame.blocksize, pred_order);
+
+    uint64_t bits = 8 + pred_order * sub->obits + 2 + sub->rc.coding_mode;
+    if (sub->type == FLAC_SUBFRAME_LPC)
+        bits += 4 + 5 + pred_order * s->options.lpc_coeff_precision;
+    bits += calc_rice_params(&sub->rc, pmin, pmax, sub->residual,
+                             s->frame.blocksize, pred_order);
+    return bits;
+}
+
+
+static void encode_residual_fixed(int32_t *res, const int32_t *smp, int n,
+                                  int order)
+{
+    int i;
+
+    for (i = 0; i < order; i++)
+        res[i] = smp[i];
+
+    if (order == 0) {
+        for (i = order; i < n; i++)
+            res[i] = smp[i];
+    } else if (order == 1) {
+        for (i = order; i < n; i++)
+            res[i] = smp[i] - smp[i-1];
+    } else if (order == 2) {
+        int a = smp[order-1] - smp[order-2];
+        for (i = order; i < n; i += 2) {
+            int b    = smp[i  ] - smp[i-1];
+            res[i]   = b - a;
+            a        = smp[i+1] - smp[i  ];
+            res[i+1] = a - b;
+        }
+    } else if (order == 3) {
+        int a = smp[order-1] -   smp[order-2];
+        int c = smp[order-1] - 2*smp[order-2] + smp[order-3];
+        for (i = order; i < n; i += 2) {
+            int b    = smp[i  ] - smp[i-1];
+            int d    = b - a;
+            res[i]   = d - c;
+            a        = smp[i+1] - smp[i  ];
+            c        = a - b;
+            res[i+1] = c - d;
+        }
+    } else {
+        int a = smp[order-1] -   smp[order-2];
+        int c = smp[order-1] - 2*smp[order-2] +   smp[order-3];
+        int e = smp[order-1] - 3*smp[order-2] + 3*smp[order-3] - smp[order-4];
+        for (i = order; i < n; i += 2) {
+            int b    = smp[i  ] - smp[i-1];
+            int d    = b - a;
+            int f    = d - c;
+            res[i  ] = f - e;
+            a        = smp[i+1] - smp[i  ];
+            c        = a - b;
+            e        = c - d;
+            res[i+1] = e - f;
+        }
+    }
+}
+
+
+static int encode_residual_ch(FlacEncodeContext *s, int ch)
+{
+    int i, n;
+    int min_order, max_order, opt_order, omethod;
+    FlacFrame *frame;
+    FlacSubframe *sub;
+    int32_t coefs[MAX_LPC_ORDER][MAX_LPC_ORDER];
+    int shift[MAX_LPC_ORDER];
+    int32_t *res, *smp;
+
+    frame = &s->frame;
+    sub   = &frame->subframes[ch];
+    res   = sub->residual;
+    smp   = sub->samples;
+    n     = frame->blocksize;
+
+    /* CONSTANT */
+    for (i = 1; i < n; i++)
+        if(smp[i] != smp[0])
+            break;
+    if (i == n) {
+        sub->type = sub->type_code = FLAC_SUBFRAME_CONSTANT;
+        res[0] = smp[0];
+        return subframe_count_exact(s, sub, 0);
+    }
+
+    /* VERBATIM */
+    if (frame->verbatim_only || n < 5) {
+        sub->type = sub->type_code = FLAC_SUBFRAME_VERBATIM;
+        memcpy(res, smp, n * sizeof(int32_t));
+        return subframe_count_exact(s, sub, 0);
+    }
+
+    min_order  = s->options.min_prediction_order;
+    max_order  = s->options.max_prediction_order;
+    omethod    = s->options.prediction_order_method;
+
+    /* FIXED */
+    sub->type = FLAC_SUBFRAME_FIXED;
+    if (s->options.lpc_type == FF_LPC_TYPE_NONE  ||
+        s->options.lpc_type == FF_LPC_TYPE_FIXED || n <= max_order) {
+        uint64_t bits[MAX_FIXED_ORDER+1];
+        if (max_order > MAX_FIXED_ORDER)
+            max_order = MAX_FIXED_ORDER;
+        opt_order = 0;
+        bits[0]   = UINT32_MAX;
+        for (i = min_order; i <= max_order; i++) {
+            encode_residual_fixed(res, smp, n, i);
+            bits[i] = find_subframe_rice_params(s, sub, i);
+            if (bits[i] < bits[opt_order])
+                opt_order = i;
+        }
+        sub->order     = opt_order;
+        sub->type_code = sub->type | sub->order;
+        if (sub->order != max_order) {
+            encode_residual_fixed(res, smp, n, sub->order);
+            find_subframe_rice_params(s, sub, sub->order);
+        }
+        return subframe_count_exact(s, sub, sub->order);
+    }
+
+    /* LPC */
+    sub->type = FLAC_SUBFRAME_LPC;
+    opt_order = ff_lpc_calc_coefs(&s->lpc_ctx, smp, n, min_order, max_order,
+                                  s->options.lpc_coeff_precision, coefs, shift, s->options.lpc_type,
+                                  s->options.lpc_passes, omethod,
+                                  MAX_LPC_SHIFT, 0);
+
+    if (omethod == ORDER_METHOD_2LEVEL ||
+        omethod == ORDER_METHOD_4LEVEL ||
+        omethod == ORDER_METHOD_8LEVEL) {
+        int levels = 1 << omethod;
+        uint64_t bits[1 << ORDER_METHOD_8LEVEL];
+        int order       = -1;
+        int opt_index   = levels-1;
+        opt_order       = max_order-1;
+        bits[opt_index] = UINT32_MAX;
+        for (i = levels-1; i >= 0; i--) {
+            int last_order = order;
+            order = min_order + (((max_order-min_order+1) * (i+1)) / levels)-1;
+            order = av_clip(order, min_order - 1, max_order - 1);
+            if (order == last_order)
+                continue;
+            s->flac_dsp.lpc_encode(res, smp, n, order+1, coefs[order],
+                                   shift[order]);
+            bits[i] = find_subframe_rice_params(s, sub, order+1);
+            if (bits[i] < bits[opt_index]) {
+                opt_index = i;
+                opt_order = order;
+            }
+        }
+        opt_order++;
+    } else if (omethod == ORDER_METHOD_SEARCH) {
+        // brute-force optimal order search
+        uint64_t bits[MAX_LPC_ORDER];
+        opt_order = 0;
+        bits[0]   = UINT32_MAX;
+        for (i = min_order-1; i < max_order; i++) {
+            s->flac_dsp.lpc_encode(res, smp, n, i+1, coefs[i], shift[i]);
+            bits[i] = find_subframe_rice_params(s, sub, i+1);
+            if (bits[i] < bits[opt_order])
+                opt_order = i;
+        }
+        opt_order++;
+    } else if (omethod == ORDER_METHOD_LOG) {
+        uint64_t bits[MAX_LPC_ORDER];
+        int step;
+
+        opt_order = min_order - 1 + (max_order-min_order)/3;
+        memset(bits, -1, sizeof(bits));
+
+        for (step = 16; step; step >>= 1) {
+            int last = opt_order;
+            for (i = last-step; i <= last+step; i += step) {
+                if (i < min_order-1 || i >= max_order || bits[i] < UINT32_MAX)
+                    continue;
+                s->flac_dsp.lpc_encode(res, smp, n, i+1, coefs[i], shift[i]);
+                bits[i] = find_subframe_rice_params(s, sub, i+1);
+                if (bits[i] < bits[opt_order])
+                    opt_order = i;
+            }
+        }
+        opt_order++;
+    }
+
+    sub->order     = opt_order;
+    sub->type_code = sub->type | (sub->order-1);
+    sub->shift     = shift[sub->order-1];
+    for (i = 0; i < sub->order; i++)
+        sub->coefs[i] = coefs[sub->order-1][i];
+
+    s->flac_dsp.lpc_encode(res, smp, n, sub->order, sub->coefs, sub->shift);
+
+    find_subframe_rice_params(s, sub, sub->order);
+
+    return subframe_count_exact(s, sub, sub->order);
+}
+
+
+static int count_frame_header(FlacEncodeContext *s)
+{
+    uint8_t av_unused tmp;
+    int count;
+
+    /*
+    <14> Sync code
+    <1>  Reserved
+    <1>  Blocking strategy
+    <4>  Block size in inter-channel samples
+    <4>  Sample rate
+    <4>  Channel assignment
+    <3>  Sample size in bits
+    <1>  Reserved
+    */
+    count = 32;
+
+    /* coded frame number */
+    PUT_UTF8(s->frame_count, tmp, count += 8;)
+
+    /* explicit block size */
+    if (s->frame.bs_code[0] == 6)
+        count += 8;
+    else if (s->frame.bs_code[0] == 7)
+        count += 16;
+
+    /* explicit sample rate */
+    count += ((s->sr_code[0] == 12) + (s->sr_code[0] > 12)) * 8;
+
+    /* frame header CRC-8 */
+    count += 8;
+
+    return count;
+}
+
+
+static int encode_frame(FlacEncodeContext *s)
+{
+    int ch;
+    uint64_t count;
+
+    count = count_frame_header(s);
+
+    for (ch = 0; ch < s->channels; ch++)
+        count += encode_residual_ch(s, ch);
+
+    count += (8 - (count & 7)) & 7; // byte alignment
+    count += 16;                    // CRC-16
+
+    count >>= 3;
+    if (count > INT_MAX)
+        return AVERROR_BUG;
+    return count;
+}
+
+
+static void remove_wasted_bits(FlacEncodeContext *s)
+{
+    int ch, i;
+
+    for (ch = 0; ch < s->channels; ch++) {
+        FlacSubframe *sub = &s->frame.subframes[ch];
+        int32_t v         = 0;
+
+        for (i = 0; i < s->frame.blocksize; i++) {
+            v |= sub->samples[i];
+            if (v & 1)
+                break;
+        }
+
+        if (v && !(v & 1)) {
+            v = av_ctz(v);
+
+            for (i = 0; i < s->frame.blocksize; i++)
+                sub->samples[i] >>= v;
+
+            sub->wasted = v;
+            sub->obits -= v;
+
+            /* for 24-bit, check if removing wasted bits makes the range better
+               suited for using RICE instead of RICE2 for entropy coding */
+            if (sub->obits <= 17)
+                sub->rc.coding_mode = CODING_MODE_RICE;
+        }
+    }
+}
+
+
+static int estimate_stereo_mode(int32_t *left_ch, int32_t *right_ch, int n,
+                                int max_rice_param)
+{
+    int i, best;
+    int32_t lt, rt;
+    uint64_t sum[4];
+    uint64_t score[4];
+    int k;
+
+    /* calculate sum of 2nd order residual for each channel */
+    sum[0] = sum[1] = sum[2] = sum[3] = 0;
+    for (i = 2; i < n; i++) {
+        lt = left_ch[i]  - 2*left_ch[i-1]  + left_ch[i-2];
+        rt = right_ch[i] - 2*right_ch[i-1] + right_ch[i-2];
+        sum[2] += FFABS((lt + rt) >> 1);
+        sum[3] += FFABS(lt - rt);
+        sum[0] += FFABS(lt);
+        sum[1] += FFABS(rt);
+    }
+    /* estimate bit counts */
+    for (i = 0; i < 4; i++) {
+        k      = find_optimal_param(2 * sum[i], n, max_rice_param);
+        sum[i] = rice_encode_count( 2 * sum[i], n, k);
+    }
+
+    /* calculate score for each mode */
+    score[0] = sum[0] + sum[1];
+    score[1] = sum[0] + sum[3];
+    score[2] = sum[1] + sum[3];
+    score[3] = sum[2] + sum[3];
+
+    /* return mode with lowest score */
+    best = 0;
+    for (i = 1; i < 4; i++)
+        if (score[i] < score[best])
+            best = i;
+
+    return best;
+}
+
+
+/**
+ * Perform stereo channel decorrelation.
+ */
+static void channel_decorrelation(FlacEncodeContext *s)
+{
+    FlacFrame *frame;
+    int32_t *left, *right;
+    int i, n;
+
+    frame = &s->frame;
+    n     = frame->blocksize;
+    left  = frame->subframes[0].samples;
+    right = frame->subframes[1].samples;
+
+    if (s->channels != 2) {
+        frame->ch_mode = FLAC_CHMODE_INDEPENDENT;
+        return;
+    }
+
+    if (s->options.ch_mode < 0) {
+        int max_rice_param = (1 << frame->subframes[0].rc.coding_mode) - 2;
+        frame->ch_mode = estimate_stereo_mode(left, right, n, max_rice_param);
+    } else
+        frame->ch_mode = s->options.ch_mode;
+
+    /* perform decorrelation and adjust bits-per-sample */
+    if (frame->ch_mode == FLAC_CHMODE_INDEPENDENT)
+        return;
+    if (frame->ch_mode == FLAC_CHMODE_MID_SIDE) {
+        int32_t tmp;
+        for (i = 0; i < n; i++) {
+            tmp      = left[i];
+            left[i]  = (tmp + right[i]) >> 1;
+            right[i] =  tmp - right[i];
+        }
+        frame->subframes[1].obits++;
+    } else if (frame->ch_mode == FLAC_CHMODE_LEFT_SIDE) {
+        for (i = 0; i < n; i++)
+            right[i] = left[i] - right[i];
+        frame->subframes[1].obits++;
+    } else {
+        for (i = 0; i < n; i++)
+            left[i] -= right[i];
+        frame->subframes[0].obits++;
+    }
+}
+
+
+static void write_utf8(PutBitContext *pb, uint32_t val)
+{
+    uint8_t tmp;
+    PUT_UTF8(val, tmp, put_bits(pb, 8, tmp);)
+}
+
+
+static void write_frame_header(FlacEncodeContext *s)
+{
+    FlacFrame *frame;
+    int crc;
+
+    frame = &s->frame;
+
+    put_bits(&s->pb, 16, 0xFFF8);
+    put_bits(&s->pb, 4, frame->bs_code[0]);
+    put_bits(&s->pb, 4, s->sr_code[0]);
+
+    if (frame->ch_mode == FLAC_CHMODE_INDEPENDENT)
+        put_bits(&s->pb, 4, s->channels-1);
+    else
+        put_bits(&s->pb, 4, frame->ch_mode + FLAC_MAX_CHANNELS - 1);
+
+    put_bits(&s->pb, 3, s->bps_code);
+    put_bits(&s->pb, 1, 0);
+    write_utf8(&s->pb, s->frame_count);
+
+    if (frame->bs_code[0] == 6)
+        put_bits(&s->pb, 8, frame->bs_code[1]);
+    else if (frame->bs_code[0] == 7)
+        put_bits(&s->pb, 16, frame->bs_code[1]);
+
+    if (s->sr_code[0] == 12)
+        put_bits(&s->pb, 8, s->sr_code[1]);
+    else if (s->sr_code[0] > 12)
+        put_bits(&s->pb, 16, s->sr_code[1]);
+
+    flush_put_bits(&s->pb);
+    crc = av_crc(av_crc_get_table(AV_CRC_8_ATM), 0, s->pb.buf,
+                 put_bits_count(&s->pb) >> 3);
+    put_bits(&s->pb, 8, crc);
+}
+
+
+static void write_subframes(FlacEncodeContext *s)
+{
+    int ch;
+
+    for (ch = 0; ch < s->channels; ch++) {
+        FlacSubframe *sub = &s->frame.subframes[ch];
+        int i, p, porder, psize;
+        int32_t *part_end;
+        int32_t *res       =  sub->residual;
+        int32_t *frame_end = &sub->residual[s->frame.blocksize];
+
+        /* subframe header */
+        put_bits(&s->pb, 1, 0);
+        put_bits(&s->pb, 6, sub->type_code);
+        put_bits(&s->pb, 1, !!sub->wasted);
+        if (sub->wasted)
+            put_bits(&s->pb, sub->wasted, 1);
+
+        /* subframe */
+        if (sub->type == FLAC_SUBFRAME_CONSTANT) {
+            put_sbits(&s->pb, sub->obits, res[0]);
+        } else if (sub->type == FLAC_SUBFRAME_VERBATIM) {
+            while (res < frame_end)
+                put_sbits(&s->pb, sub->obits, *res++);
+        } else {
+            /* warm-up samples */
+            for (i = 0; i < sub->order; i++)
+                put_sbits(&s->pb, sub->obits, *res++);
+
+            /* LPC coefficients */
+            if (sub->type == FLAC_SUBFRAME_LPC) {
+                int cbits = s->options.lpc_coeff_precision;
+                put_bits( &s->pb, 4, cbits-1);
+                put_sbits(&s->pb, 5, sub->shift);
+                for (i = 0; i < sub->order; i++)
+                    put_sbits(&s->pb, cbits, sub->coefs[i]);
+            }
+
+            /* rice-encoded block */
+            put_bits(&s->pb, 2, sub->rc.coding_mode - 4);
+
+            /* partition order */
+            porder  = sub->rc.porder;
+            psize   = s->frame.blocksize >> porder;
+            put_bits(&s->pb, 4, porder);
+
+            /* residual */
+            part_end  = &sub->residual[psize];
+            for (p = 0; p < 1 << porder; p++) {
+                int k = sub->rc.params[p];
+                put_bits(&s->pb, sub->rc.coding_mode, k);
+                while (res < part_end)
+                    set_sr_golomb_flac(&s->pb, *res++, k, INT32_MAX, 0);
+                part_end = FFMIN(frame_end, part_end + psize);
+            }
+        }
+    }
+}
+
+
+static void write_frame_footer(FlacEncodeContext *s)
+{
+    int crc;
+    flush_put_bits(&s->pb);
+    crc = av_bswap16(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, s->pb.buf,
+                            put_bits_count(&s->pb)>>3));
+    put_bits(&s->pb, 16, crc);
+    flush_put_bits(&s->pb);
+}
+
+
+static int write_frame(FlacEncodeContext *s, AVPacket *avpkt)
+{
+    init_put_bits(&s->pb, avpkt->data, avpkt->size);
+    write_frame_header(s);
+    write_subframes(s);
+    write_frame_footer(s);
+    return put_bits_count(&s->pb) >> 3;
+}
+
+
+static int update_md5_sum(FlacEncodeContext *s, const void *samples)
+{
+    const uint8_t *buf;
+    int buf_size = s->frame.blocksize * s->channels *
+                   ((s->avctx->bits_per_raw_sample + 7) / 8);
+
+    if (s->avctx->bits_per_raw_sample > 16 || HAVE_BIGENDIAN) {
+        av_fast_malloc(&s->md5_buffer, &s->md5_buffer_size, buf_size);
+        if (!s->md5_buffer)
+            return AVERROR(ENOMEM);
+    }
+
+    if (s->avctx->bits_per_raw_sample <= 16) {
+        buf = (const uint8_t *)samples;
+#if HAVE_BIGENDIAN
+        s->dsp.bswap16_buf((uint16_t *)s->md5_buffer,
+                           (const uint16_t *)samples, buf_size / 2);
+        buf = s->md5_buffer;
+#endif
+    } else {
+        int i;
+        const int32_t *samples0 = samples;
+        uint8_t *tmp            = s->md5_buffer;
+
+        for (i = 0; i < s->frame.blocksize * s->channels; i++) {
+            int32_t v = samples0[i] >> 8;
+            *tmp++    = (v      ) & 0xFF;
+            *tmp++    = (v >>  8) & 0xFF;
+            *tmp++    = (v >> 16) & 0xFF;
+        }
+        buf = s->md5_buffer;
+    }
+    av_md5_update(s->md5ctx, buf, buf_size);
+
+    return 0;
+}
+
+
+static int flac_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
+                             const AVFrame *frame, int *got_packet_ptr)
+{
+    FlacEncodeContext *s;
+    int frame_bytes, out_bytes, ret;
+
+    s = avctx->priv_data;
+
+    /* when the last block is reached, update the header in extradata */
+    if (!frame) {
+        s->max_framesize = s->max_encoded_framesize;
+        av_md5_final(s->md5ctx, s->md5sum);
+        write_streaminfo(s, avctx->extradata);
+        return 0;
+    }
+
+    /* change max_framesize for small final frame */
+    if (frame->nb_samples < s->frame.blocksize) {
+        s->max_framesize = ff_flac_get_max_frame_size(frame->nb_samples,
+                                                      s->channels,
+                                                      avctx->bits_per_raw_sample);
+    }
+
+    init_frame(s, frame->nb_samples);
+
+    copy_samples(s, frame->data[0]);
+
+    channel_decorrelation(s);
+
+    remove_wasted_bits(s);
+
+    frame_bytes = encode_frame(s);
+
+    /* fallback to verbatim mode if the compressed frame is larger than it
+       would be if encoded uncompressed. */
+    if (frame_bytes < 0 || frame_bytes > s->max_framesize) {
+        s->frame.verbatim_only = 1;
+        frame_bytes = encode_frame(s);
+        if (frame_bytes < 0) {
+            av_log(avctx, AV_LOG_ERROR, "Bad frame count\n");
+            return frame_bytes;
+        }
+    }
+
+    if ((ret = ff_alloc_packet2(avctx, avpkt, frame_bytes)) < 0)
+        return ret;
+
+    out_bytes = write_frame(s, avpkt);
+
+    s->frame_count++;
+    s->sample_count += frame->nb_samples;
+    if ((ret = update_md5_sum(s, frame->data[0])) < 0) {
+        av_log(avctx, AV_LOG_ERROR, "Error updating MD5 checksum\n");
+        return ret;
+    }
+    if (out_bytes > s->max_encoded_framesize)
+        s->max_encoded_framesize = out_bytes;
+    if (out_bytes < s->min_framesize)
+        s->min_framesize = out_bytes;
+
+    avpkt->pts      = frame->pts;
+    avpkt->duration = ff_samples_to_time_base(avctx, frame->nb_samples);
+    avpkt->size     = out_bytes;
+    *got_packet_ptr = 1;
+    return 0;
+}
+
+
+static av_cold int flac_encode_close(AVCodecContext *avctx)
+{
+    if (avctx->priv_data) {
+        FlacEncodeContext *s = avctx->priv_data;
+        av_freep(&s->md5ctx);
+        av_freep(&s->md5_buffer);
+        ff_lpc_end(&s->lpc_ctx);
+    }
+    av_freep(&avctx->extradata);
+    avctx->extradata_size = 0;
+    return 0;
+}
+
+#define FLAGS AV_OPT_FLAG_ENCODING_PARAM | AV_OPT_FLAG_AUDIO_PARAM
+static const AVOption options[] = {
+{ "lpc_coeff_precision", "LPC coefficient precision", offsetof(FlacEncodeContext, options.lpc_coeff_precision), AV_OPT_TYPE_INT, {.i64 = 15 }, 0, MAX_LPC_PRECISION, FLAGS },
+{ "lpc_type", "LPC algorithm", offsetof(FlacEncodeContext, options.lpc_type), AV_OPT_TYPE_INT, {.i64 = FF_LPC_TYPE_DEFAULT }, FF_LPC_TYPE_DEFAULT, FF_LPC_TYPE_NB-1, FLAGS, "lpc_type" },
+{ "none",     NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_NONE },     INT_MIN, INT_MAX, FLAGS, "lpc_type" },
+{ "fixed",    NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_FIXED },    INT_MIN, INT_MAX, FLAGS, "lpc_type" },
+{ "levinson", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_LEVINSON }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
+{ "cholesky", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_LPC_TYPE_CHOLESKY }, INT_MIN, INT_MAX, FLAGS, "lpc_type" },
+{ "lpc_passes", "Number of passes to use for Cholesky factorization during LPC analysis", offsetof(FlacEncodeContext, options.lpc_passes),  AV_OPT_TYPE_INT, {.i64 = 2 }, 1, INT_MAX, FLAGS },
+{ "min_partition_order",  NULL, offsetof(FlacEncodeContext, options.min_partition_order),  AV_OPT_TYPE_INT, {.i64 = -1 },      -1, MAX_PARTITION_ORDER, FLAGS },
+{ "max_partition_order",  NULL, offsetof(FlacEncodeContext, options.max_partition_order),  AV_OPT_TYPE_INT, {.i64 = -1 },      -1, MAX_PARTITION_ORDER, FLAGS },
+{ "prediction_order_method", "Search method for selecting prediction order", offsetof(FlacEncodeContext, options.prediction_order_method), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, ORDER_METHOD_LOG, FLAGS, "predm" },
+{ "estimation", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_EST },    INT_MIN, INT_MAX, FLAGS, "predm" },
+{ "2level",     NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_2LEVEL }, INT_MIN, INT_MAX, FLAGS, "predm" },
+{ "4level",     NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_4LEVEL }, INT_MIN, INT_MAX, FLAGS, "predm" },
+{ "8level",     NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_8LEVEL }, INT_MIN, INT_MAX, FLAGS, "predm" },
+{ "search",     NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_SEARCH }, INT_MIN, INT_MAX, FLAGS, "predm" },
+{ "log",        NULL, 0, AV_OPT_TYPE_CONST, {.i64 = ORDER_METHOD_LOG },    INT_MIN, INT_MAX, FLAGS, "predm" },
+{ "ch_mode", "Stereo decorrelation mode", offsetof(FlacEncodeContext, options.ch_mode), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, FLAC_CHMODE_MID_SIDE, FLAGS, "ch_mode" },
+{ "auto",       NULL, 0, AV_OPT_TYPE_CONST, { .i64 = -1                      }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
+{ "indep",      NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_INDEPENDENT }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
+{ "left_side",  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_LEFT_SIDE   }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
+{ "right_side", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_RIGHT_SIDE  }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
+{ "mid_side",   NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FLAC_CHMODE_MID_SIDE    }, INT_MIN, INT_MAX, FLAGS, "ch_mode" },
+{ NULL },
+};
+
+static const AVClass flac_encoder_class = {
+    "FLAC encoder",
+    av_default_item_name,
+    options,
+    LIBAVUTIL_VERSION_INT,
+};
+
+AVCodec ff_flac_encoder = {
+    .name           = "flac",
+    .type           = AVMEDIA_TYPE_AUDIO,
+    .id             = AV_CODEC_ID_FLAC,
+    .priv_data_size = sizeof(FlacEncodeContext),
+    .init           = flac_encode_init,
+    .encode2        = flac_encode_frame,
+    .close          = flac_encode_close,
+    .capabilities   = CODEC_CAP_SMALL_LAST_FRAME | CODEC_CAP_DELAY | CODEC_CAP_LOSSLESS,
+    .sample_fmts    = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
+                                                     AV_SAMPLE_FMT_S32,
+                                                     AV_SAMPLE_FMT_NONE },
+    .long_name      = NULL_IF_CONFIG_SMALL("FLAC (Free Lossless Audio Codec)"),
+    .priv_class     = &flac_encoder_class,
+};