mirror of https://github.com/FFmpeg/FFmpeg.git
* commit 'a42e3a6700547e4e49445bda81d3a89ec3e081a9': pcm_dvd: consolidate pieces from pcm.c and mpeg.c Conflicts: libavcodec/pcm.c libavcodec/version.h libavformat/mpeg.c Merged-by: Michael Niedermayer <michaelni@gmx.at>pull/35/head
Michael Niedermayer
12 years ago
commit
cb4d05e7f2
5 changed files with 293 additions and 71 deletions
@ -0,0 +1,289 @@ |
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/*
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* LPCM codecs for PCM formats found in Video DVD streams |
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* Copyright (c) 2009-2013 Christian Schmidt |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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/**
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* @file |
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* LPCM codecs for PCM formats found in Video DVD streams |
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*/ |
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#include "avcodec.h" |
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#include "bytestream.h" |
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#include "internal.h" |
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typedef struct PCMDVDContext { |
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uint32_t last_header; // Cached header to see if parsing is needed
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int block_size; // Size of a block of samples in bytes
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int samples_per_block; // Number of samples per channel per block
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int groups_per_block; // Number of 20/24bit sample groups per block
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uint8_t *extra_samples; // Pointer to leftover samples from a frame
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int extra_sample_count; // Number of leftover samples in the buffer
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} PCMDVDContext; |
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static av_cold int pcm_dvd_decode_init(AVCodecContext *avctx) |
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{ |
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PCMDVDContext *s = avctx->priv_data; |
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/* Invalid header to force parsing of the first header */ |
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s->last_header = -1; |
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/* reserve space for 8 channels, 3 bytes/sample, 4 samples/block */ |
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if (!(s->extra_samples = av_malloc(8 * 3 * 4))) |
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return AVERROR(ENOMEM); |
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s->extra_sample_count = 0; |
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return 0; |
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} |
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static av_cold int pcm_dvd_decode_uninit(AVCodecContext *avctx) |
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{ |
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PCMDVDContext *s = avctx->priv_data; |
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if (s->extra_samples) |
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av_free(s->extra_samples); |
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return 0; |
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} |
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static int pcm_dvd_parse_header(AVCodecContext *avctx, const uint8_t *header) |
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{ |
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/* no traces of 44100 and 32000Hz in any commercial software or player */ |
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static const uint32_t frequencies[4] = { 48000, 96000, 44100, 32000 }; |
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PCMDVDContext *s = avctx->priv_data; |
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int header_int = (header[0] & 0xe0) | (header[1] << 8) | (header[2] << 16); |
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/* early exit if the header didn't change apart from the frame number */ |
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if (s->last_header == header_int) |
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return 0; |
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if (avctx->debug & FF_DEBUG_PICT_INFO) |
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av_dlog(avctx, "pcm_dvd_parse_header: header = %02x%02x%02x\n", |
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header[0], header[1], header[2]); |
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/*
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* header[0] emphasis (1), muse(1), reserved(1), frame number(5) |
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* header[1] quant (2), freq(2), reserved(1), channels(3) |
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* header[2] dynamic range control (0x80 = off) |
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*/ |
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/* get the sample depth and derive the sample format from it */ |
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avctx->bits_per_coded_sample = 16 + (header[1] >> 6 & 3) * 4; |
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if (avctx->bits_per_coded_sample == 28) { |
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av_log(avctx, AV_LOG_ERROR, |
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"PCM DVD unsupported sample depth %i\n", |
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avctx->bits_per_coded_sample); |
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return AVERROR_INVALIDDATA; |
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} |
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avctx->sample_fmt = avctx->bits_per_coded_sample == 16 ? AV_SAMPLE_FMT_S16 |
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: AV_SAMPLE_FMT_S32; |
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avctx->bits_per_raw_sample = avctx->bits_per_coded_sample; |
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/* get the sample rate */ |
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avctx->sample_rate = frequencies[header[1] >> 4 & 3]; |
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/* get the number of channels */ |
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avctx->channels = 1 + (header[1] & 7); |
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/* calculate the bitrate */ |
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avctx->bit_rate = avctx->channels * |
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avctx->sample_rate * |
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avctx->bits_per_coded_sample; |
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/* 4 samples form a group in 20/24bit PCM on DVD Video.
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* A block is formed by the number of groups that are |
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* needed to complete a set of samples for each channel. */ |
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if (avctx->bits_per_coded_sample == 16) { |
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s->samples_per_block = 1; |
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s->block_size = avctx->channels * 2; |
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} else { |
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switch (avctx->channels) { |
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case 1: |
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case 2: |
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case 4: |
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/* one group has all the samples needed */ |
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s->block_size = 4 * avctx->bits_per_coded_sample / 8; |
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s->samples_per_block = 4 / avctx->channels; |
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s->groups_per_block = 1; |
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break; |
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case 8: |
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/* two groups have all the samples needed */ |
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s->block_size = 8 * avctx->bits_per_coded_sample / 8; |
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s->samples_per_block = 1; |
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s->groups_per_block = 2; |
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break; |
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default: |
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/* need avctx->channels groups */ |
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s->block_size = 4 * avctx->channels * |
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avctx->bits_per_coded_sample / 8; |
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s->samples_per_block = 4; |
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s->groups_per_block = avctx->channels; |
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break; |
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} |
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} |
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if (avctx->debug & FF_DEBUG_PICT_INFO) |
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av_dlog(avctx, |
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"pcm_dvd_parse_header: %d channels, %d bits per sample, %d Hz, %d bit/s\n", |
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avctx->channels, avctx->bits_per_coded_sample, |
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avctx->sample_rate, avctx->bit_rate); |
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s->last_header = header_int; |
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return 0; |
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} |
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static void *pcm_dvd_decode_samples(AVCodecContext *avctx, const uint8_t *src, |
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void *dst, int blocks) |
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{ |
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PCMDVDContext *s = avctx->priv_data; |
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int16_t *dst16 = dst; |
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int32_t *dst32 = dst; |
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GetByteContext gb; |
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int i; |
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uint8_t t; |
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int samples; |
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bytestream2_init(&gb, src, blocks * s->block_size); |
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switch (avctx->bits_per_coded_sample) { |
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case 16: |
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#if HAVE_BIGENDIAN |
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bytestream2_get_buffer(&gb, dst16, blocks * s->block_size); |
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dst16 += blocks * block_size / 2; |
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#else |
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samples = blocks * avctx->channels; |
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do { |
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*dst16++ = bytestream2_get_be16u(&gb); |
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} while (--samples); |
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#endif |
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return dst16; |
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case 20: |
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do { |
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for (i = s->groups_per_block; i; i--) { |
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dst32[0] = bytestream2_get_be16u(&gb) << 16; |
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dst32[1] = bytestream2_get_be16u(&gb) << 16; |
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dst32[2] = bytestream2_get_be16u(&gb) << 16; |
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dst32[3] = bytestream2_get_be16u(&gb) << 16; |
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t = bytestream2_get_byteu(&gb); |
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*dst32 += (t & 0xf0) << 8; |
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*dst32 += (t & 0x0f) << 12; |
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t = bytestream2_get_byteu(&gb); |
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*dst32 += (t & 0xf0) << 8; |
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*dst32 += (t & 0x0f) << 12; |
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} |
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} while (--blocks); |
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return dst32; |
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case 24: |
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do { |
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for (i = s->groups_per_block; i; i--) { |
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dst32[0] = bytestream2_get_be16u(&gb) << 16; |
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dst32[1] = bytestream2_get_be16u(&gb) << 16; |
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dst32[2] = bytestream2_get_be16u(&gb) << 16; |
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dst32[3] = bytestream2_get_be16u(&gb) << 16; |
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*dst32++ += bytestream2_get_byteu(&gb) << 8; |
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*dst32++ += bytestream2_get_byteu(&gb) << 8; |
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*dst32++ += bytestream2_get_byteu(&gb) << 8; |
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*dst32++ += bytestream2_get_byteu(&gb) << 8; |
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} |
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} while (--blocks); |
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return dst32; |
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default: |
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return NULL; |
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} |
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} |
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static int pcm_dvd_decode_frame(AVCodecContext *avctx, void *data, |
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int *got_frame_ptr, AVPacket *avpkt) |
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{ |
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AVFrame *frame = data; |
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const uint8_t *src = avpkt->data; |
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int buf_size = avpkt->size; |
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PCMDVDContext *s = avctx->priv_data; |
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int retval; |
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int blocks; |
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void *dst; |
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if (buf_size < 3) { |
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av_log(avctx, AV_LOG_ERROR, "PCM packet too small\n"); |
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return AVERROR_INVALIDDATA; |
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} |
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if ((retval = pcm_dvd_parse_header(avctx, src))) |
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return retval; |
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src += 3; |
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buf_size -= 3; |
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blocks = (buf_size + s->extra_sample_count) / s->block_size; |
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/* get output buffer */ |
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frame->nb_samples = blocks * s->samples_per_block; |
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if ((retval = ff_get_buffer(avctx, frame, 0)) < 0) { |
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av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); |
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return retval; |
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} |
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dst = frame->data[0]; |
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/* consume leftover samples from last packet */ |
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if (s->extra_sample_count) { |
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int missing_samples = s->block_size - s->extra_sample_count; |
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if (buf_size >= missing_samples) { |
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memcpy(s->extra_samples + s->extra_sample_count, src, |
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missing_samples); |
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dst = pcm_dvd_decode_samples(avctx, s->extra_samples, dst, 1); |
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src += missing_samples; |
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buf_size -= missing_samples; |
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s->extra_sample_count = 0; |
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blocks--; |
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} else { |
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/* new packet still doesn't have enough samples */ |
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memcpy(s->extra_samples + s->extra_sample_count, src, buf_size); |
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s->extra_sample_count += buf_size; |
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return avpkt->size; |
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} |
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} |
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/* decode remaining complete samples */ |
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if (blocks) { |
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pcm_dvd_decode_samples(avctx, src, dst, blocks); |
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buf_size -= blocks * s->block_size; |
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} |
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/* store leftover samples */ |
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if (buf_size) { |
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src += blocks * s->block_size; |
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memcpy(s->extra_samples, src, buf_size); |
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s->extra_sample_count = buf_size; |
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} |
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*got_frame_ptr = 1; |
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return avpkt->size; |
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} |
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AVCodec ff_pcm_dvd_decoder = { |
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.name = "pcm_dvd", |
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.long_name = NULL_IF_CONFIG_SMALL("PCM signed 16|20|24-bit big-endian for DVD media"), |
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.type = AVMEDIA_TYPE_AUDIO, |
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.id = AV_CODEC_ID_PCM_DVD, |
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.priv_data_size = sizeof(PCMDVDContext), |
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.init = pcm_dvd_decode_init, |
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.decode = pcm_dvd_decode_frame, |
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.close = pcm_dvd_decode_uninit, |
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.capabilities = CODEC_CAP_DR1, |
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.sample_fmts = (const enum AVSampleFormat[]) { |
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AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_NONE |
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} |
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}; |
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