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Diffstat (limited to 'ffmpeg/libavcodec/8svx.c')
-rw-r--r--ffmpeg/libavcodec/8svx.c216
1 files changed, 216 insertions, 0 deletions
diff --git a/ffmpeg/libavcodec/8svx.c b/ffmpeg/libavcodec/8svx.c
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+++ b/ffmpeg/libavcodec/8svx.c
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+/*
+ * Copyright (C) 2008 Jaikrishnan Menon
+ * Copyright (C) 2011 Stefano Sabatini
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * 8svx audio decoder
+ * @author Jaikrishnan Menon
+ *
+ * supports: fibonacci delta encoding
+ * : exponential encoding
+ *
+ * For more information about the 8SVX format:
+ * http://netghost.narod.ru/gff/vendspec/iff/iff.txt
+ * http://sox.sourceforge.net/AudioFormats-11.html
+ * http://aminet.net/package/mus/misc/wavepak
+ * http://amigan.1emu.net/reg/8SVX.txt
+ *
+ * Samples can be found here:
+ * http://aminet.net/mods/smpl/
+ */
+
+#include "libavutil/avassert.h"
+#include "avcodec.h"
+#include "internal.h"
+#include "libavutil/common.h"
+
+/** decoder context */
+typedef struct EightSvxContext {
+ uint8_t fib_acc[2];
+ const int8_t *table;
+
+ /* buffer used to store the whole first packet.
+ data is only sent as one large packet */
+ uint8_t *data[2];
+ int data_size;
+ int data_idx;
+} EightSvxContext;
+
+static const int8_t fibonacci[16] = { -34, -21, -13, -8, -5, -3, -2, -1, 0, 1, 2, 3, 5, 8, 13, 21 };
+static const int8_t exponential[16] = { -128, -64, -32, -16, -8, -4, -2, -1, 0, 1, 2, 4, 8, 16, 32, 64 };
+
+#define MAX_FRAME_SIZE 2048
+
+/**
+ * Delta decode the compressed values in src, and put the resulting
+ * decoded samples in dst.
+ *
+ * @param[in,out] state starting value. it is saved for use in the next call.
+ * @param table delta sequence table
+ */
+static void delta_decode(uint8_t *dst, const uint8_t *src, int src_size,
+ uint8_t *state, const int8_t *table)
+{
+ uint8_t val = *state;
+
+ while (src_size--) {
+ uint8_t d = *src++;
+ val = av_clip_uint8(val + table[d & 0xF]);
+ *dst++ = val;
+ val = av_clip_uint8(val + table[d >> 4]);
+ *dst++ = val;
+ }
+
+ *state = val;
+}
+
+/** decode a frame */
+static int eightsvx_decode_frame(AVCodecContext *avctx, void *data,
+ int *got_frame_ptr, AVPacket *avpkt)
+{
+ EightSvxContext *esc = avctx->priv_data;
+ AVFrame *frame = data;
+ int buf_size;
+ int ch, ret;
+ int hdr_size = 2;
+
+ /* decode and interleave the first packet */
+ if (!esc->data[0] && avpkt) {
+ int chan_size = avpkt->size / avctx->channels - hdr_size;
+
+ if (avpkt->size % avctx->channels) {
+ av_log(avctx, AV_LOG_WARNING, "Packet with odd size, ignoring last byte\n");
+ }
+ if (avpkt->size < (hdr_size + 1) * avctx->channels) {
+ av_log(avctx, AV_LOG_ERROR, "packet size is too small\n");
+ return AVERROR(EINVAL);
+ }
+
+ esc->fib_acc[0] = avpkt->data[1] + 128;
+ if (avctx->channels == 2)
+ esc->fib_acc[1] = avpkt->data[2+chan_size+1] + 128;
+
+ esc->data_idx = 0;
+ esc->data_size = chan_size;
+ if (!(esc->data[0] = av_malloc(chan_size)))
+ return AVERROR(ENOMEM);
+ if (avctx->channels == 2) {
+ if (!(esc->data[1] = av_malloc(chan_size))) {
+ av_freep(&esc->data[0]);
+ return AVERROR(ENOMEM);
+ }
+ }
+ memcpy(esc->data[0], &avpkt->data[hdr_size], chan_size);
+ if (avctx->channels == 2)
+ memcpy(esc->data[1], &avpkt->data[2*hdr_size+chan_size], chan_size);
+ }
+ if (!esc->data[0]) {
+ av_log(avctx, AV_LOG_ERROR, "unexpected empty packet\n");
+ return AVERROR(EINVAL);
+ }
+
+ /* decode next piece of data from the buffer */
+ buf_size = FFMIN(MAX_FRAME_SIZE, esc->data_size - esc->data_idx);
+ if (buf_size <= 0) {
+ *got_frame_ptr = 0;
+ return avpkt->size;
+ }
+
+ /* get output buffer */
+ frame->nb_samples = buf_size * 2;
+ if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
+ return ret;
+
+ for (ch = 0; ch < avctx->channels; ch++) {
+ delta_decode(frame->data[ch], &esc->data[ch][esc->data_idx],
+ buf_size, &esc->fib_acc[ch], esc->table);
+ }
+
+ esc->data_idx += buf_size;
+
+ *got_frame_ptr = 1;
+
+ return ((avctx->frame_number == 0)*hdr_size + buf_size)*avctx->channels;
+}
+
+static av_cold int eightsvx_decode_init(AVCodecContext *avctx)
+{
+ EightSvxContext *esc = avctx->priv_data;
+
+ if (avctx->channels < 1 || avctx->channels > 2) {
+ av_log(avctx, AV_LOG_ERROR, "8SVX does not support more than 2 channels\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ switch (avctx->codec->id) {
+ case AV_CODEC_ID_8SVX_FIB: esc->table = fibonacci; break;
+ case AV_CODEC_ID_8SVX_EXP: esc->table = exponential; break;
+ default:
+ av_log(avctx, AV_LOG_ERROR, "Invalid codec id %d.\n", avctx->codec->id);
+ return AVERROR_INVALIDDATA;
+ }
+ avctx->sample_fmt = AV_SAMPLE_FMT_U8P;
+
+ return 0;
+}
+
+static av_cold int eightsvx_decode_close(AVCodecContext *avctx)
+{
+ EightSvxContext *esc = avctx->priv_data;
+
+ av_freep(&esc->data[0]);
+ av_freep(&esc->data[1]);
+ esc->data_size = 0;
+ esc->data_idx = 0;
+
+ return 0;
+}
+
+#if CONFIG_EIGHTSVX_FIB_DECODER
+AVCodec ff_eightsvx_fib_decoder = {
+ .name = "8svx_fib",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .id = AV_CODEC_ID_8SVX_FIB,
+ .priv_data_size = sizeof (EightSvxContext),
+ .init = eightsvx_decode_init,
+ .decode = eightsvx_decode_frame,
+ .close = eightsvx_decode_close,
+ .capabilities = CODEC_CAP_DR1,
+ .long_name = NULL_IF_CONFIG_SMALL("8SVX fibonacci"),
+ .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P,
+ AV_SAMPLE_FMT_NONE },
+};
+#endif
+#if CONFIG_EIGHTSVX_EXP_DECODER
+AVCodec ff_eightsvx_exp_decoder = {
+ .name = "8svx_exp",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .id = AV_CODEC_ID_8SVX_EXP,
+ .priv_data_size = sizeof (EightSvxContext),
+ .init = eightsvx_decode_init,
+ .decode = eightsvx_decode_frame,
+ .close = eightsvx_decode_close,
+ .capabilities = CODEC_CAP_DR1,
+ .long_name = NULL_IF_CONFIG_SMALL("8SVX exponential"),
+ .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P,
+ AV_SAMPLE_FMT_NONE },
+};
+#endif
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