making act segmenter

1 files changed, 1023 insertions, 0 deletions

diff --git a/ffmpeg/libavformat/nutenc.c b/ffmpeg/libavformat/nutenc.c
new file mode 100644
index 0000000..2d8d265
--- /dev/null
+++ b/ffmpeg/libavformat/nutenc.c
@@ -0,0 +1,1023 @@
+/*
+ * nut muxer
+ * Copyright (c) 2004-2007 Michael Niedermayer
+ *
+ * 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/intreadwrite.h"
+#include "libavutil/mathematics.h"
+#include "libavutil/tree.h"
+#include "libavutil/dict.h"
+#include "libavutil/avassert.h"
+#include "libavcodec/mpegaudiodata.h"
+#include "nut.h"
+#include "internal.h"
+#include "avio_internal.h"
+#include "riff.h"
+
+static int find_expected_header(AVCodecContext *c, int size, int key_frame,
+                                uint8_t out[64])
+{
+    int sample_rate = c->sample_rate;
+
+    if (size > 4096)
+        return 0;
+
+    AV_WB24(out, 1);
+
+    if (c->codec_id == AV_CODEC_ID_MPEG4) {
+        if (key_frame) {
+            return 3;
+        } else {
+            out[3] = 0xB6;
+            return 4;
+        }
+    } else if (c->codec_id == AV_CODEC_ID_MPEG1VIDEO ||
+               c->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
+        return 3;
+    } else if (c->codec_id == AV_CODEC_ID_H264) {
+        return 3;
+    } else if (c->codec_id == AV_CODEC_ID_MP3 ||
+               c->codec_id == AV_CODEC_ID_MP2) {
+        int lsf, mpeg25, sample_rate_index, bitrate_index, frame_size;
+        int layer           = c->codec_id == AV_CODEC_ID_MP3 ? 3 : 2;
+        unsigned int header = 0xFFF00000;
+
+        lsf           = sample_rate < (24000 + 32000) / 2;
+        mpeg25        = sample_rate < (12000 + 16000) / 2;
+        sample_rate <<= lsf + mpeg25;
+        if      (sample_rate < (32000 + 44100) / 2) sample_rate_index = 2;
+        else if (sample_rate < (44100 + 48000) / 2) sample_rate_index = 0;
+        else                                        sample_rate_index = 1;
+
+        sample_rate = avpriv_mpa_freq_tab[sample_rate_index] >> (lsf + mpeg25);
+
+        for (bitrate_index = 2; bitrate_index < 30; bitrate_index++) {
+            frame_size =
+                avpriv_mpa_bitrate_tab[lsf][layer - 1][bitrate_index >> 1];
+            frame_size = (frame_size * 144000) / (sample_rate << lsf) +
+                (bitrate_index & 1);
+
+            if (frame_size == size)
+                break;
+        }
+
+        header |= (!lsf) << 19;
+        header |= (4 - layer) << 17;
+        header |= 1 << 16; //no crc
+        AV_WB32(out, header);
+        if (size <= 0)
+            return 2;  //we guess there is no crc, if there is one the user clearly does not care about overhead
+        if (bitrate_index == 30)
+            return -1;  //something is wrong ...
+
+        header |= (bitrate_index >> 1) << 12;
+        header |= sample_rate_index << 10;
+        header |= (bitrate_index & 1) << 9;
+
+        return 2; //FIXME actually put the needed ones in build_elision_headers()
+        return 3; //we guess that the private bit is not set
+//FIXME the above assumptions should be checked, if these turn out false too often something should be done
+    }
+    return 0;
+}
+
+static int find_header_idx(AVFormatContext *s, AVCodecContext *c, int size, int frame_type)
+{
+    NUTContext *nut = s->priv_data;
+    uint8_t out[64];
+    int i;
+    int len = find_expected_header(c, size, frame_type, out);
+
+    for (i = 1; i < nut->header_count; i++) {
+        if (len == nut->header_len[i] && !memcmp(out, nut->header[i], len)) {
+            return i;
+        }
+    }
+
+    return 0;
+}
+
+static void build_elision_headers(AVFormatContext *s)
+{
+    NUTContext *nut = s->priv_data;
+    int i;
+    //FIXME this is lame
+    //FIXME write a 2pass mode to find the maximal headers
+    static const uint8_t headers[][5] = {
+        { 3, 0x00, 0x00, 0x01 },
+        { 4, 0x00, 0x00, 0x01, 0xB6},
+        { 2, 0xFF, 0xFA }, //mp3+crc
+        { 2, 0xFF, 0xFB }, //mp3
+        { 2, 0xFF, 0xFC }, //mp2+crc
+        { 2, 0xFF, 0xFD }, //mp2
+    };
+
+    nut->header_count = 7;
+    for (i = 1; i < nut->header_count; i++) {
+        nut->header_len[i] = headers[i - 1][0];
+        nut->header[i]     = &headers[i - 1][1];
+    }
+}
+
+static void build_frame_code(AVFormatContext *s)
+{
+    NUTContext *nut = s->priv_data;
+    int key_frame, index, pred, stream_id;
+    int start = 1;
+    int end   = 254;
+    int keyframe_0_esc = s->nb_streams > 2;
+    int pred_table[10];
+    FrameCode *ft;
+
+    ft            = &nut->frame_code[start];
+    ft->flags     = FLAG_CODED;
+    ft->size_mul  = 1;
+    ft->pts_delta = 1;
+    start++;
+
+    if (keyframe_0_esc) {
+        /* keyframe = 0 escape */
+        FrameCode *ft = &nut->frame_code[start];
+        ft->flags    = FLAG_STREAM_ID | FLAG_SIZE_MSB | FLAG_CODED_PTS;
+        ft->size_mul = 1;
+        start++;
+    }
+
+    for (stream_id = 0; stream_id < s->nb_streams; stream_id++) {
+        int start2 = start + (end - start) * stream_id       / s->nb_streams;
+        int end2   = start + (end - start) * (stream_id + 1) / s->nb_streams;
+        AVCodecContext *codec = s->streams[stream_id]->codec;
+        int is_audio          = codec->codec_type == AVMEDIA_TYPE_AUDIO;
+        int intra_only        = /*codec->intra_only || */ is_audio;
+        int pred_count;
+        int frame_size = 0;
+
+        if (codec->codec_type == AVMEDIA_TYPE_AUDIO) {
+            frame_size = av_get_audio_frame_duration(codec, 0);
+            if (codec->codec_id == AV_CODEC_ID_VORBIS && !frame_size)
+                frame_size = 64;
+        } else {
+            AVRational f = av_div_q(codec->time_base, *nut->stream[stream_id].time_base);
+            if (f.den == 1 && f.num>0)
+                frame_size = f.num;
+        }
+        if (!frame_size)
+            frame_size = 1;
+
+        for (key_frame = 0; key_frame < 2; key_frame++) {
+            if (!intra_only || !keyframe_0_esc || key_frame != 0) {
+                FrameCode *ft = &nut->frame_code[start2];
+                ft->flags     = FLAG_KEY * key_frame;
+                ft->flags    |= FLAG_SIZE_MSB | FLAG_CODED_PTS;
+                ft->stream_id = stream_id;
+                ft->size_mul  = 1;
+                if (is_audio)
+                    ft->header_idx = find_header_idx(s, codec, -1, key_frame);
+                start2++;
+            }
+        }
+
+        key_frame = intra_only;
+#if 1
+        if (is_audio) {
+            int frame_bytes = codec->frame_size * (int64_t)codec->bit_rate /
+                              (8 * codec->sample_rate);
+            int pts;
+            for (pts = 0; pts < 2; pts++) {
+                for (pred = 0; pred < 2; pred++) {
+                    FrameCode *ft  = &nut->frame_code[start2];
+                    ft->flags      = FLAG_KEY * key_frame;
+                    ft->stream_id  = stream_id;
+                    ft->size_mul   = frame_bytes + 2;
+                    ft->size_lsb   = frame_bytes + pred;
+                    ft->pts_delta  = pts * frame_size;
+                    ft->header_idx = find_header_idx(s, codec, frame_bytes + pred, key_frame);
+                    start2++;
+                }
+            }
+        } else {
+            FrameCode *ft = &nut->frame_code[start2];
+            ft->flags     = FLAG_KEY | FLAG_SIZE_MSB;
+            ft->stream_id = stream_id;
+            ft->size_mul  = 1;
+            ft->pts_delta = frame_size;
+            start2++;
+        }
+#endif
+
+        if (codec->has_b_frames) {
+            pred_count    = 5;
+            pred_table[0] = -2;
+            pred_table[1] = -1;
+            pred_table[2] = 1;
+            pred_table[3] = 3;
+            pred_table[4] = 4;
+        } else if (codec->codec_id == AV_CODEC_ID_VORBIS) {
+            pred_count    = 3;
+            pred_table[0] = 2;
+            pred_table[1] = 9;
+            pred_table[2] = 16;
+        } else {
+            pred_count    = 1;
+            pred_table[0] = 1;
+        }
+
+        for (pred = 0; pred < pred_count; pred++) {
+            int start3 = start2 + (end2 - start2) * pred / pred_count;
+            int end3   = start2 + (end2 - start2) * (pred + 1) / pred_count;
+
+            pred_table[pred] *= frame_size;
+
+            for (index = start3; index < end3; index++) {
+                FrameCode *ft = &nut->frame_code[index];
+                ft->flags     = FLAG_KEY * key_frame;
+                ft->flags    |= FLAG_SIZE_MSB;
+                ft->stream_id = stream_id;
+//FIXME use single byte size and pred from last
+                ft->size_mul  = end3 - start3;
+                ft->size_lsb  = index - start3;
+                ft->pts_delta = pred_table[pred];
+                if (is_audio)
+                    ft->header_idx = find_header_idx(s, codec, -1, key_frame);
+            }
+        }
+    }
+    memmove(&nut->frame_code['N' + 1], &nut->frame_code['N'], sizeof(FrameCode) * (255 - 'N'));
+    nut->frame_code[0].flags       =
+        nut->frame_code[255].flags =
+        nut->frame_code['N'].flags = FLAG_INVALID;
+}
+
+static void put_tt(NUTContext *nut, AVRational *time_base, AVIOContext *bc, uint64_t val)
+{
+    val *= nut->time_base_count;
+    val += time_base - nut->time_base;
+    ff_put_v(bc, val);
+}
+/**
+ * Store a string as vb.
+ */
+static void put_str(AVIOContext *bc, const char *string)
+{
+    int len = strlen(string);
+
+    ff_put_v(bc, len);
+    avio_write(bc, string, len);
+}
+
+static void put_s(AVIOContext *bc, int64_t val)
+{
+    ff_put_v(bc, 2 * FFABS(val) - (val > 0));
+}
+
+#ifdef TRACE
+static inline void ff_put_v_trace(AVIOContext *bc, uint64_t v, const char *file,
+                                  const char *func, int line)
+{
+    av_log(NULL, AV_LOG_DEBUG, "ff_put_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
+
+    ff_put_v(bc, v);
+}
+
+static inline void put_s_trace(AVIOContext *bc, int64_t v, const char *file, const char *func, int line)
+{
+    av_log(NULL, AV_LOG_DEBUG, "put_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
+
+    put_s(bc, v);
+}
+#define ff_put_v(bc, v)  ff_put_v_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
+#define put_s(bc, v)  put_s_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
+#endif
+
+//FIXME remove calculate_checksum
+static void put_packet(NUTContext *nut, AVIOContext *bc, AVIOContext *dyn_bc,
+                       int calculate_checksum, uint64_t startcode)
+{
+    uint8_t *dyn_buf = NULL;
+    int dyn_size     = avio_close_dyn_buf(dyn_bc, &dyn_buf);
+    int forw_ptr     = dyn_size + 4 * calculate_checksum;
+
+    if (forw_ptr > 4096)
+        ffio_init_checksum(bc, ff_crc04C11DB7_update, 0);
+    avio_wb64(bc, startcode);
+    ff_put_v(bc, forw_ptr);
+    if (forw_ptr > 4096)
+        avio_wl32(bc, ffio_get_checksum(bc));
+
+    if (calculate_checksum)
+        ffio_init_checksum(bc, ff_crc04C11DB7_update, 0);
+    avio_write(bc, dyn_buf, dyn_size);
+    if (calculate_checksum)
+        avio_wl32(bc, ffio_get_checksum(bc));
+
+    av_free(dyn_buf);
+}
+
+static void write_mainheader(NUTContext *nut, AVIOContext *bc)
+{
+    int i, j, tmp_pts, tmp_flags, tmp_stream, tmp_mul, tmp_size, tmp_fields,
+        tmp_head_idx;
+    int64_t tmp_match;
+
+    ff_put_v(bc, 3); /* version */
+    ff_put_v(bc, nut->avf->nb_streams);
+    ff_put_v(bc, nut->max_distance);
+    ff_put_v(bc, nut->time_base_count);
+
+    for (i = 0; i < nut->time_base_count; i++) {
+        ff_put_v(bc, nut->time_base[i].num);
+        ff_put_v(bc, nut->time_base[i].den);
+    }
+
+    tmp_pts      = 0;
+    tmp_mul      = 1;
+    tmp_stream   = 0;
+    tmp_match    = 1 - (1LL << 62);
+    tmp_head_idx = 0;
+    for (i = 0; i < 256; ) {
+        tmp_fields = 0;
+        tmp_size   = 0;
+//        tmp_res=0;
+        if (tmp_pts      != nut->frame_code[i].pts_delta ) tmp_fields = 1;
+        if (tmp_mul      != nut->frame_code[i].size_mul  ) tmp_fields = 2;
+        if (tmp_stream   != nut->frame_code[i].stream_id ) tmp_fields = 3;
+        if (tmp_size     != nut->frame_code[i].size_lsb  ) tmp_fields = 4;
+//        if (tmp_res    != nut->frame_code[i].res            ) tmp_fields=5;
+        if (tmp_head_idx != nut->frame_code[i].header_idx) tmp_fields = 8;
+
+        tmp_pts    = nut->frame_code[i].pts_delta;
+        tmp_flags  = nut->frame_code[i].flags;
+        tmp_stream = nut->frame_code[i].stream_id;
+        tmp_mul    = nut->frame_code[i].size_mul;
+        tmp_size   = nut->frame_code[i].size_lsb;
+//        tmp_res   = nut->frame_code[i].res;
+        tmp_head_idx = nut->frame_code[i].header_idx;
+
+        for (j = 0; i < 256; j++, i++) {
+            if (i == 'N') {
+                j--;
+                continue;
+            }
+            if (nut->frame_code[i].pts_delta  != tmp_pts      ||
+                nut->frame_code[i].flags      != tmp_flags    ||
+                nut->frame_code[i].stream_id  != tmp_stream   ||
+                nut->frame_code[i].size_mul   != tmp_mul      ||
+                nut->frame_code[i].size_lsb   != tmp_size + j ||
+//              nut->frame_code[i].res        != tmp_res      ||
+                nut->frame_code[i].header_idx != tmp_head_idx)
+                break;
+        }
+        if (j != tmp_mul - tmp_size)
+            tmp_fields = 6;
+
+        ff_put_v(bc, tmp_flags);
+        ff_put_v(bc, tmp_fields);
+        if (tmp_fields > 0) put_s(bc, tmp_pts);
+        if (tmp_fields > 1) ff_put_v(bc, tmp_mul);
+        if (tmp_fields > 2) ff_put_v(bc, tmp_stream);
+        if (tmp_fields > 3) ff_put_v(bc, tmp_size);
+        if (tmp_fields > 4) ff_put_v(bc, 0 /*tmp_res*/);
+        if (tmp_fields > 5) ff_put_v(bc, j);
+        if (tmp_fields > 6) ff_put_v(bc, tmp_match);
+        if (tmp_fields > 7) ff_put_v(bc, tmp_head_idx);
+    }
+    ff_put_v(bc, nut->header_count - 1);
+    for (i = 1; i < nut->header_count; i++) {
+        ff_put_v(bc, nut->header_len[i]);
+        avio_write(bc, nut->header[i], nut->header_len[i]);
+    }
+}
+
+static int write_streamheader(AVFormatContext *avctx, AVIOContext *bc,
+                              AVStream *st, int i)
+{
+    NUTContext *nut       = avctx->priv_data;
+    AVCodecContext *codec = st->codec;
+
+    ff_put_v(bc, i);
+    switch (codec->codec_type) {
+    case AVMEDIA_TYPE_VIDEO:    ff_put_v(bc, 0); break;
+    case AVMEDIA_TYPE_AUDIO:    ff_put_v(bc, 1); break;
+    case AVMEDIA_TYPE_SUBTITLE: ff_put_v(bc, 2); break;
+    default:                    ff_put_v(bc, 3); break;
+    }
+    ff_put_v(bc, 4);
+    if (codec->codec_tag) {
+        avio_wl32(bc, codec->codec_tag);
+    } else {
+        av_log(avctx, AV_LOG_ERROR, "No codec tag defined for stream %d\n", i);
+        return AVERROR(EINVAL);
+    }
+
+    ff_put_v(bc, nut->stream[i].time_base - nut->time_base);
+    ff_put_v(bc, nut->stream[i].msb_pts_shift);
+    ff_put_v(bc, nut->stream[i].max_pts_distance);
+    ff_put_v(bc, codec->has_b_frames);
+    avio_w8(bc, 0); /* flags: 0x1 - fixed_fps, 0x2 - index_present */
+
+    ff_put_v(bc, codec->extradata_size);
+    avio_write(bc, codec->extradata, codec->extradata_size);
+
+    switch (codec->codec_type) {
+    case AVMEDIA_TYPE_AUDIO:
+        ff_put_v(bc, codec->sample_rate);
+        ff_put_v(bc, 1);
+        ff_put_v(bc, codec->channels);
+        break;
+    case AVMEDIA_TYPE_VIDEO:
+        ff_put_v(bc, codec->width);
+        ff_put_v(bc, codec->height);
+
+        if (st->sample_aspect_ratio.num <= 0 ||
+            st->sample_aspect_ratio.den <= 0) {
+            ff_put_v(bc, 0);
+            ff_put_v(bc, 0);
+        } else {
+            ff_put_v(bc, st->sample_aspect_ratio.num);
+            ff_put_v(bc, st->sample_aspect_ratio.den);
+        }
+        ff_put_v(bc, 0); /* csp type -- unknown */
+        break;
+    default:
+        break;
+    }
+    return 0;
+}
+
+static int add_info(AVIOContext *bc, const char *type, const char *value)
+{
+    put_str(bc, type);
+    put_s(bc, -1);
+    put_str(bc, value);
+    return 1;
+}
+
+static int write_globalinfo(NUTContext *nut, AVIOContext *bc)
+{
+    AVFormatContext *s   = nut->avf;
+    AVDictionaryEntry *t = NULL;
+    AVIOContext *dyn_bc;
+    uint8_t *dyn_buf = NULL;
+    int count        = 0, dyn_size;
+    int ret          = avio_open_dyn_buf(&dyn_bc);
+    if (ret < 0)
+        return ret;
+
+    while ((t = av_dict_get(s->metadata, "", t, AV_DICT_IGNORE_SUFFIX)))
+        count += add_info(dyn_bc, t->key, t->value);
+
+    ff_put_v(bc, 0); //stream_if_plus1
+    ff_put_v(bc, 0); //chapter_id
+    ff_put_v(bc, 0); //timestamp_start
+    ff_put_v(bc, 0); //length
+
+    ff_put_v(bc, count);
+
+    dyn_size = avio_close_dyn_buf(dyn_bc, &dyn_buf);
+    avio_write(bc, dyn_buf, dyn_size);
+    av_free(dyn_buf);
+    return 0;
+}
+
+static int write_streaminfo(NUTContext *nut, AVIOContext *bc, int stream_id) {
+    AVFormatContext *s= nut->avf;
+    AVStream* st = s->streams[stream_id];
+    AVDictionaryEntry *t = NULL;
+    AVIOContext *dyn_bc;
+    uint8_t *dyn_buf=NULL;
+    int count=0, dyn_size, i;
+    int ret = avio_open_dyn_buf(&dyn_bc);
+    if (ret < 0)
+        return ret;
+
+    while ((t = av_dict_get(st->metadata, "", t, AV_DICT_IGNORE_SUFFIX)))
+        count += add_info(dyn_bc, t->key, t->value);
+    for (i=0; ff_nut_dispositions[i].flag; ++i) {
+        if (st->disposition & ff_nut_dispositions[i].flag)
+            count += add_info(dyn_bc, "Disposition", ff_nut_dispositions[i].str);
+    }
+    if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
+        uint8_t buf[256];
+        snprintf(buf, sizeof(buf), "%d/%d", st->codec->time_base.den, st->codec->time_base.num);
+        count += add_info(dyn_bc, "r_frame_rate", buf);
+    }
+    dyn_size = avio_close_dyn_buf(dyn_bc, &dyn_buf);
+
+    if (count) {
+        ff_put_v(bc, stream_id + 1); //stream_id_plus1
+        ff_put_v(bc, 0); //chapter_id
+        ff_put_v(bc, 0); //timestamp_start
+        ff_put_v(bc, 0); //length
+
+        ff_put_v(bc, count);
+
+        avio_write(bc, dyn_buf, dyn_size);
+    }
+
+    av_free(dyn_buf);
+    return count;
+}
+
+static int write_chapter(NUTContext *nut, AVIOContext *bc, int id)
+{
+    AVIOContext *dyn_bc;
+    uint8_t *dyn_buf     = NULL;
+    AVDictionaryEntry *t = NULL;
+    AVChapter *ch        = nut->avf->chapters[id];
+    int ret, dyn_size, count = 0;
+
+    ret = avio_open_dyn_buf(&dyn_bc);
+    if (ret < 0)
+        return ret;
+
+    ff_put_v(bc, 0);                                        // stream_id_plus1
+    put_s(bc, id + 1);                                      // chapter_id
+    put_tt(nut, nut->chapter[id].time_base, bc, ch->start); // chapter_start
+    ff_put_v(bc, ch->end - ch->start);                      // chapter_len
+
+    while ((t = av_dict_get(ch->metadata, "", t, AV_DICT_IGNORE_SUFFIX)))
+        count += add_info(dyn_bc, t->key, t->value);
+
+    ff_put_v(bc, count);
+
+    dyn_size = avio_close_dyn_buf(dyn_bc, &dyn_buf);
+    avio_write(bc, dyn_buf, dyn_size);
+    av_freep(&dyn_buf);
+    return 0;
+}
+
+static int write_index(NUTContext *nut, AVIOContext *bc) {
+    int i;
+    Syncpoint dummy= { .pos= 0 };
+    Syncpoint *next_node[2] = { NULL };
+    int64_t startpos = avio_tell(bc);
+    int64_t payload_size;
+
+    put_tt(nut, nut->max_pts_tb, bc, nut->max_pts);
+
+    ff_put_v(bc, nut->sp_count);
+
+    for (i=0; i<nut->sp_count; i++) {
+        av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pos_cmp, (void**)next_node);
+        ff_put_v(bc, (next_node[1]->pos >> 4) - (dummy.pos>>4));
+        dummy.pos = next_node[1]->pos;
+    }
+
+    for (i=0; i<nut->avf->nb_streams; i++) {
+        StreamContext *nus= &nut->stream[i];
+        int64_t last_pts= -1;
+        int j, k;
+        for (j=0; j<nut->sp_count; j++) {
+            int flag = (nus->keyframe_pts[j] != AV_NOPTS_VALUE) ^ (j+1 == nut->sp_count);
+            int n = 0;
+            for (; j<nut->sp_count && (nus->keyframe_pts[j] != AV_NOPTS_VALUE) == flag; j++)
+                n++;
+
+            ff_put_v(bc, 1 + 2*flag + 4*n);
+            for (k= j - n; k<=j && k<nut->sp_count; k++) {
+                if (nus->keyframe_pts[k] == AV_NOPTS_VALUE)
+                    continue;
+                av_assert0(nus->keyframe_pts[k] > last_pts);
+                ff_put_v(bc, nus->keyframe_pts[k] - last_pts);
+                last_pts = nus->keyframe_pts[k];
+            }
+        }
+    }
+
+    payload_size = avio_tell(bc) - startpos + 8 + 4;
+
+    avio_wb64(bc, 8 + payload_size + av_log2(payload_size) / 7 + 1 + 4*(payload_size > 4096));
+
+    return 0;
+}
+
+static int write_headers(AVFormatContext *avctx, AVIOContext *bc)
+{
+    NUTContext *nut = avctx->priv_data;
+    AVIOContext *dyn_bc;
+    int i, ret;
+
+    ff_metadata_conv_ctx(avctx, ff_nut_metadata_conv, NULL);
+
+    ret = avio_open_dyn_buf(&dyn_bc);
+    if (ret < 0)
+        return ret;
+    write_mainheader(nut, dyn_bc);
+    put_packet(nut, bc, dyn_bc, 1, MAIN_STARTCODE);
+
+    for (i = 0; i < nut->avf->nb_streams; i++) {
+        ret = avio_open_dyn_buf(&dyn_bc);
+        if (ret < 0)
+            return ret;
+        ret = write_streamheader(avctx, dyn_bc, nut->avf->streams[i], i);
+        if (ret < 0)
+            return ret;
+        put_packet(nut, bc, dyn_bc, 1, STREAM_STARTCODE);
+    }
+
+    ret = avio_open_dyn_buf(&dyn_bc);
+    if (ret < 0)
+        return ret;
+    write_globalinfo(nut, dyn_bc);
+    put_packet(nut, bc, dyn_bc, 1, INFO_STARTCODE);
+
+    for (i = 0; i < nut->avf->nb_streams; i++) {
+        ret = avio_open_dyn_buf(&dyn_bc);
+        if (ret < 0)
+            return ret;
+        ret = write_streaminfo(nut, dyn_bc, i);
+        if (ret < 0)
+            return ret;
+        if (ret > 0)
+            put_packet(nut, bc, dyn_bc, 1, INFO_STARTCODE);
+        else {
+            uint8_t *buf;
+            avio_close_dyn_buf(dyn_bc, &buf);
+            av_free(buf);
+        }
+    }
+
+    for (i = 0; i < nut->avf->nb_chapters; i++) {
+        ret = avio_open_dyn_buf(&dyn_bc);
+        if (ret < 0)
+            return ret;
+        ret = write_chapter(nut, dyn_bc, i);
+        if (ret < 0) {
+            uint8_t *buf;
+            avio_close_dyn_buf(dyn_bc, &buf);
+            av_freep(&buf);
+            return ret;
+        }
+        put_packet(nut, bc, dyn_bc, 1, INFO_STARTCODE);
+    }
+
+    nut->last_syncpoint_pos = INT_MIN;
+    nut->header_count++;
+    return 0;
+}
+
+static int nut_write_header(AVFormatContext *s)
+{
+    NUTContext *nut = s->priv_data;
+    AVIOContext *bc = s->pb;
+    int i, j, ret;
+
+    nut->avf = s;
+
+    nut->stream   = av_mallocz(sizeof(StreamContext ) * s->nb_streams);
+    nut->chapter  = av_mallocz(sizeof(ChapterContext) * s->nb_chapters);
+    nut->time_base= av_mallocz(sizeof(AVRational    ) *(s->nb_streams +
+                                                        s->nb_chapters));
+    if (!nut->stream || !nut->chapter || !nut->time_base) {
+        av_freep(&nut->stream);
+        av_freep(&nut->chapter);
+        av_freep(&nut->time_base);
+        return AVERROR(ENOMEM);
+    }
+
+    for (i = 0; i < s->nb_streams; i++) {
+        AVStream *st = s->streams[i];
+        int ssize;
+        AVRational time_base;
+        ff_parse_specific_params(st->codec, &time_base.den, &ssize, &time_base.num);
+
+        if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO && st->codec->sample_rate) {
+            time_base = (AVRational) {1, st->codec->sample_rate};
+        } else {
+            time_base = ff_choose_timebase(s, st, 48000);
+        }
+
+        avpriv_set_pts_info(st, 64, time_base.num, time_base.den);
+
+        for (j = 0; j < nut->time_base_count; j++)
+            if (!memcmp(&time_base, &nut->time_base[j], sizeof(AVRational))) {
+                break;
+            }
+        nut->time_base[j]        = time_base;
+        nut->stream[i].time_base = &nut->time_base[j];
+        if (j == nut->time_base_count)
+            nut->time_base_count++;
+
+        if (INT64_C(1000) * time_base.num >= time_base.den)
+            nut->stream[i].msb_pts_shift = 7;
+        else
+            nut->stream[i].msb_pts_shift = 14;
+        nut->stream[i].max_pts_distance =
+            FFMAX(time_base.den, time_base.num) / time_base.num;
+    }
+
+    for (i = 0; i < s->nb_chapters; i++) {
+        AVChapter *ch = s->chapters[i];
+
+        for (j = 0; j < nut->time_base_count; j++)
+            if (!memcmp(&ch->time_base, &nut->time_base[j], sizeof(AVRational)))
+                break;
+
+        nut->time_base[j]         = ch->time_base;
+        nut->chapter[i].time_base = &nut->time_base[j];
+        if (j == nut->time_base_count)
+            nut->time_base_count++;
+    }
+
+    nut->max_distance = MAX_DISTANCE;
+    build_elision_headers(s);
+    build_frame_code(s);
+    av_assert0(nut->frame_code['N'].flags == FLAG_INVALID);
+
+    avio_write(bc, ID_STRING, strlen(ID_STRING));
+    avio_w8(bc, 0);
+
+    if ((ret = write_headers(s, bc)) < 0)
+        return ret;
+
+    if (s->avoid_negative_ts < 0)
+        s->avoid_negative_ts = 1;
+
+    avio_flush(bc);
+
+    return 0;
+}
+
+static int get_needed_flags(NUTContext *nut, StreamContext *nus, FrameCode *fc,
+                            AVPacket *pkt)
+{
+    int flags = 0;
+
+    if (pkt->flags & AV_PKT_FLAG_KEY)
+        flags |= FLAG_KEY;
+    if (pkt->stream_index != fc->stream_id)
+        flags |= FLAG_STREAM_ID;
+    if (pkt->size / fc->size_mul)
+        flags |= FLAG_SIZE_MSB;
+    if (pkt->pts - nus->last_pts != fc->pts_delta)
+        flags |= FLAG_CODED_PTS;
+    if (pkt->size > 2 * nut->max_distance)
+        flags |= FLAG_CHECKSUM;
+    if (FFABS(pkt->pts - nus->last_pts) > nus->max_pts_distance)
+        flags |= FLAG_CHECKSUM;
+    if (pkt->size < nut->header_len[fc->header_idx] ||
+        (pkt->size > 4096 && fc->header_idx)        ||
+        memcmp(pkt->data, nut->header[fc->header_idx],
+               nut->header_len[fc->header_idx]))
+        flags |= FLAG_HEADER_IDX;
+
+    return flags | (fc->flags & FLAG_CODED);
+}
+
+static int find_best_header_idx(NUTContext *nut, AVPacket *pkt)
+{
+    int i;
+    int best_i   = 0;
+    int best_len = 0;
+
+    if (pkt->size > 4096)
+        return 0;
+
+    for (i = 1; i < nut->header_count; i++)
+        if (pkt->size >= nut->header_len[i]
+            && nut->header_len[i] > best_len
+            && !memcmp(pkt->data, nut->header[i], nut->header_len[i])) {
+            best_i   = i;
+            best_len = nut->header_len[i];
+        }
+    return best_i;
+}
+
+static int nut_write_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    NUTContext *nut    = s->priv_data;
+    StreamContext *nus = &nut->stream[pkt->stream_index];
+    AVIOContext *bc    = s->pb, *dyn_bc;
+    FrameCode *fc;
+    int64_t coded_pts;
+    int best_length, frame_code, flags, needed_flags, i, header_idx;
+    int best_header_idx;
+    int key_frame = !!(pkt->flags & AV_PKT_FLAG_KEY);
+    int store_sp  = 0;
+    int ret;
+
+    if (pkt->pts < 0) {
+        av_log(s, AV_LOG_ERROR,
+               "Negative pts not supported stream %d, pts %"PRId64"\n",
+               pkt->stream_index, pkt->pts);
+        return AVERROR(EINVAL);
+    }
+
+    if (1LL << (20 + 3 * nut->header_count) <= avio_tell(bc))
+        write_headers(s, bc);
+
+    if (key_frame && !(nus->last_flags & FLAG_KEY))
+        store_sp = 1;
+
+    if (pkt->size + 30 /*FIXME check*/ + avio_tell(bc) >= nut->last_syncpoint_pos + nut->max_distance)
+        store_sp = 1;
+
+//FIXME: Ensure store_sp is 1 in the first place.
+
+    if (store_sp) {
+        Syncpoint *sp, dummy = { .pos = INT64_MAX };
+
+        ff_nut_reset_ts(nut, *nus->time_base, pkt->dts);
+        for (i = 0; i < s->nb_streams; i++) {
+            AVStream *st   = s->streams[i];
+            int64_t dts_tb = av_rescale_rnd(pkt->dts,
+                nus->time_base->num * (int64_t)nut->stream[i].time_base->den,
+                nus->time_base->den * (int64_t)nut->stream[i].time_base->num,
+                AV_ROUND_DOWN);
+            int index = av_index_search_timestamp(st, dts_tb,
+                                                  AVSEEK_FLAG_BACKWARD);
+            if (index >= 0)
+                dummy.pos = FFMIN(dummy.pos, st->index_entries[index].pos);
+        }
+        if (dummy.pos == INT64_MAX)
+            dummy.pos = 0;
+        sp = av_tree_find(nut->syncpoints, &dummy, (void *)ff_nut_sp_pos_cmp,
+                          NULL);
+
+        nut->last_syncpoint_pos = avio_tell(bc);
+        ret                     = avio_open_dyn_buf(&dyn_bc);
+        if (ret < 0)
+            return ret;
+        put_tt(nut, nus->time_base, dyn_bc, pkt->dts);
+        ff_put_v(dyn_bc, sp ? (nut->last_syncpoint_pos - sp->pos) >> 4 : 0);
+        put_packet(nut, bc, dyn_bc, 1, SYNCPOINT_STARTCODE);
+
+        ff_nut_add_sp(nut, nut->last_syncpoint_pos, 0 /*unused*/, pkt->dts);
+
+        if ((1ll<<60) % nut->sp_count == 0)
+            for (i=0; i<s->nb_streams; i++) {
+                int j;
+                StreamContext *nus = &nut->stream[i];
+                nus->keyframe_pts = av_realloc(nus->keyframe_pts, 2*nut->sp_count*sizeof(*nus->keyframe_pts));
+                if (!nus->keyframe_pts)
+                    return AVERROR(ENOMEM);
+                for (j=nut->sp_count == 1 ? 0 : nut->sp_count; j<2*nut->sp_count; j++)
+                    nus->keyframe_pts[j] = AV_NOPTS_VALUE;
+        }
+    }
+    av_assert0(nus->last_pts != AV_NOPTS_VALUE);
+
+    coded_pts = pkt->pts & ((1 << nus->msb_pts_shift) - 1);
+    if (ff_lsb2full(nus, coded_pts) != pkt->pts)
+        coded_pts = pkt->pts + (1 << nus->msb_pts_shift);
+
+    best_header_idx = find_best_header_idx(nut, pkt);
+
+    best_length = INT_MAX;
+    frame_code  = -1;
+    for (i = 0; i < 256; i++) {
+        int length    = 0;
+        FrameCode *fc = &nut->frame_code[i];
+        int flags     = fc->flags;
+
+        if (flags & FLAG_INVALID)
+            continue;
+        needed_flags = get_needed_flags(nut, nus, fc, pkt);
+
+        if (flags & FLAG_CODED) {
+            length++;
+            flags = needed_flags;
+        }
+
+        if ((flags & needed_flags) != needed_flags)
+            continue;
+
+        if ((flags ^ needed_flags) & FLAG_KEY)
+            continue;
+
+        if (flags & FLAG_STREAM_ID)
+            length += ff_get_v_length(pkt->stream_index);
+
+        if (pkt->size % fc->size_mul != fc->size_lsb)
+            continue;
+        if (flags & FLAG_SIZE_MSB)
+            length += ff_get_v_length(pkt->size / fc->size_mul);
+
+        if (flags & FLAG_CHECKSUM)
+            length += 4;
+
+        if (flags & FLAG_CODED_PTS)
+            length += ff_get_v_length(coded_pts);
+
+        if (   (flags & FLAG_CODED)
+            && nut->header_len[best_header_idx] > nut->header_len[fc->header_idx] + 1) {
+            flags |= FLAG_HEADER_IDX;
+        }
+
+        if (flags & FLAG_HEADER_IDX) {
+            length += 1 - nut->header_len[best_header_idx];
+        } else {
+            length -= nut->header_len[fc->header_idx];
+        }
+
+        length *= 4;
+        length += !(flags & FLAG_CODED_PTS);
+        length += !(flags & FLAG_CHECKSUM);
+
+        if (length < best_length) {
+            best_length = length;
+            frame_code  = i;
+        }
+    }
+    av_assert0(frame_code != -1);
+    fc           = &nut->frame_code[frame_code];
+    flags        = fc->flags;
+    needed_flags = get_needed_flags(nut, nus, fc, pkt);
+    header_idx   = fc->header_idx;
+
+    ffio_init_checksum(bc, ff_crc04C11DB7_update, 0);
+    avio_w8(bc, frame_code);
+    if (flags & FLAG_CODED) {
+        ff_put_v(bc, (flags ^ needed_flags) & ~(FLAG_CODED));
+        flags = needed_flags;
+    }
+    if (flags & FLAG_STREAM_ID)  ff_put_v(bc, pkt->stream_index);
+    if (flags & FLAG_CODED_PTS)  ff_put_v(bc, coded_pts);
+    if (flags & FLAG_SIZE_MSB )  ff_put_v(bc, pkt->size / fc->size_mul);
+    if (flags & FLAG_HEADER_IDX) ff_put_v(bc, header_idx = best_header_idx);
+
+    if (flags & FLAG_CHECKSUM)   avio_wl32(bc, ffio_get_checksum(bc));
+    else                         ffio_get_checksum(bc);
+
+    avio_write(bc, pkt->data + nut->header_len[header_idx], pkt->size - nut->header_len[header_idx]);
+    nus->last_flags = flags;
+    nus->last_pts   = pkt->pts;
+
+    //FIXME just store one per syncpoint
+    if (flags & FLAG_KEY) {
+        av_add_index_entry(
+            s->streams[pkt->stream_index],
+            nut->last_syncpoint_pos,
+            pkt->pts,
+            0,
+            0,
+            AVINDEX_KEYFRAME);
+        if (nus->keyframe_pts && nus->keyframe_pts[nut->sp_count] == AV_NOPTS_VALUE)
+            nus->keyframe_pts[nut->sp_count] = pkt->pts;
+    }
+
+    if (!nut->max_pts_tb || av_compare_ts(nut->max_pts, *nut->max_pts_tb, pkt->pts, *nus->time_base) < 0) {
+        nut->max_pts = pkt->pts;
+        nut->max_pts_tb = nus->time_base;
+    }
+
+    return 0;
+}
+
+static int nut_write_trailer(AVFormatContext *s)
+{
+    NUTContext *nut = s->priv_data;
+    AVIOContext *bc = s->pb, *dyn_bc;
+    int i, ret;
+
+    while (nut->header_count < 3)
+        write_headers(s, bc);
+
+    ret = avio_open_dyn_buf(&dyn_bc);
+    if (ret >= 0 && nut->sp_count) {
+        write_index(nut, dyn_bc);
+        put_packet(nut, bc, dyn_bc, 1, INDEX_STARTCODE);
+    }
+
+    ff_nut_free_sp(nut);
+    for (i=0; i<s->nb_streams; i++)
+        av_freep(&nut->stream[i].keyframe_pts);
+
+    av_freep(&nut->stream);
+    av_freep(&nut->chapter);
+    av_freep(&nut->time_base);
+
+    return 0;
+}
+
+AVOutputFormat ff_nut_muxer = {
+    .name           = "nut",
+    .long_name      = NULL_IF_CONFIG_SMALL("NUT"),
+    .mime_type      = "video/x-nut",
+    .extensions     = "nut",
+    .priv_data_size = sizeof(NUTContext),
+    .audio_codec    = CONFIG_LIBVORBIS ? AV_CODEC_ID_VORBIS :
+                      CONFIG_LIBMP3LAME ? AV_CODEC_ID_MP3 : AV_CODEC_ID_MP2,
+    .video_codec    = AV_CODEC_ID_MPEG4,
+    .write_header   = nut_write_header,
+    .write_packet   = nut_write_packet,
+    .write_trailer  = nut_write_trailer,
+    .flags          = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
+    .codec_tag      = ff_nut_codec_tags,
+};