mirror of https://github.com/FFmpeg/FFmpeg.git
Remove the header decoding for PCM audio from mpeg.c and the 20/24bit parts from pcm.c and merge them into a new decoder in pcm-dvd.c. The decoder has added support for samples that span multiple packets and modified 20/24bit group decoding. Both is needed to decode samples that have been generated with DVD-Lab Pro 2. The decoding of 16bit PCM and two channel 24bit is identical to before. No other samples are known to verify the correctness of the encoding this software does. The complete list of tested formats is 48kHz/16bit/2-8 channels 48kHz/24bit/2-5 channels 96kHz/16bit/2-4 channels 96kHz/24bit/2 channels Signed-off-by: Luca Barbato <lu_zero@gentoo.org>pull/35/head
Christian Schmidt
11 years ago
committed by
Luca Barbato
parent
21fd2f84ce
commit
a42e3a6700
5 changed files with 291 additions and 71 deletions
@ -0,0 +1,287 @@ |
||||
/*
|
||||
* LPCM codecs for PCM formats found in Video DVD streams |
||||
* Copyright (c) 2009-2013 Christian Schmidt |
||||
* |
||||
* This file is part of Libav. |
||||
* |
||||
* Libav 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. |
||||
* |
||||
* Libav 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 Libav; if not, write to the Free Software |
||||
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
||||
*/ |
||||
|
||||
/**
|
||||
* @file |
||||
* LPCM codecs for PCM formats found in Video DVD streams |
||||
*/ |
||||
|
||||
#include "avcodec.h" |
||||
#include "bytestream.h" |
||||
#include "internal.h" |
||||
|
||||
typedef struct PCMDVDContext { |
||||
uint32_t last_header; // Cached header to see if parsing is needed
|
||||
int block_size; // Size of a block of samples in bytes
|
||||
int samples_per_block; // Number of samples per channel per block
|
||||
int groups_per_block; // Number of 20/24bit sample groups per block
|
||||
uint8_t *extra_samples; // Pointer to leftover samples from a frame
|
||||
int extra_sample_count; // Number of leftover samples in the buffer
|
||||
} PCMDVDContext; |
||||
|
||||
static av_cold int pcm_dvd_decode_init(AVCodecContext *avctx) |
||||
{ |
||||
PCMDVDContext *s = avctx->priv_data; |
||||
|
||||
/* Invalid header to force parsing of the first header */ |
||||
s->last_header = -1; |
||||
/* reserve space for 8 channels, 3 bytes/sample, 4 samples/block */ |
||||
if (!(s->extra_samples = av_malloc(8 * 3 * 4))) |
||||
return AVERROR(ENOMEM); |
||||
s->extra_sample_count = 0; |
||||
|
||||
return 0; |
||||
} |
||||
|
||||
static av_cold int pcm_dvd_decode_uninit(AVCodecContext *avctx) |
||||
{ |
||||
PCMDVDContext *s = avctx->priv_data; |
||||
|
||||
if (s->extra_samples) |
||||
av_free(s->extra_samples); |
||||
|
||||
return 0; |
||||
} |
||||
|
||||
static int pcm_dvd_parse_header(AVCodecContext *avctx, const uint8_t *header) |
||||
{ |
||||
/* no traces of 44100 and 32000Hz in any commercial software or player */ |
||||
static const uint32_t frequencies[4] = { 48000, 96000, 44100, 32000 }; |
||||
PCMDVDContext *s = avctx->priv_data; |
||||
int header_int = (header[0] & 0xe0) | (header[1] << 8) | (header[2] << 16); |
||||
|
||||
/* early exit if the header didn't change apart from the frame number */ |
||||
if (s->last_header == header_int) |
||||
return 0; |
||||
|
||||
if (avctx->debug & FF_DEBUG_PICT_INFO) |
||||
av_dlog(avctx, "pcm_dvd_parse_header: header = %02x%02x%02x\n", |
||||
header[0], header[1], header[2]); |
||||
/*
|
||||
* header[0] emphasis (1), muse(1), reserved(1), frame number(5) |
||||
* header[1] quant (2), freq(2), reserved(1), channels(3) |
||||
* header[2] dynamic range control (0x80 = off) |
||||
*/ |
||||
|
||||
/* get the sample depth and derive the sample format from it */ |
||||
avctx->bits_per_coded_sample = 16 + (header[1] >> 6 & 3) * 4; |
||||
if (avctx->bits_per_coded_sample == 28) { |
||||
av_log(avctx, AV_LOG_ERROR, "PCM DVD unsupported sample depth\n"); |
||||
return AVERROR_INVALIDDATA; |
||||
} |
||||
avctx->sample_fmt = avctx->bits_per_coded_sample == 16 ? AV_SAMPLE_FMT_S16 |
||||
: AV_SAMPLE_FMT_S32; |
||||
avctx->bits_per_raw_sample = avctx->bits_per_coded_sample; |
||||
|
||||
/* get the sample rate */ |
||||
avctx->sample_rate = frequencies[header[1] >> 4 & 3]; |
||||
|
||||
/* get the number of channels */ |
||||
avctx->channels = 1 + (header[1] & 7); |
||||
/* calculate the bitrate */ |
||||
avctx->bit_rate = avctx->channels * |
||||
avctx->sample_rate * |
||||
avctx->bits_per_coded_sample; |
||||
|
||||
/* 4 samples form a group in 20/24bit PCM on DVD Video.
|
||||
* A block is formed by the number of groups that are |
||||
* needed to complete a set of samples for each channel. */ |
||||
if (avctx->bits_per_coded_sample == 16) { |
||||
s->samples_per_block = 1; |
||||
s->block_size = avctx->channels * 2; |
||||
} else { |
||||
switch (avctx->channels) { |
||||
case 1: |
||||
case 2: |
||||
case 4: |
||||
/* one group has all the samples needed */ |
||||
s->block_size = 4 * avctx->bits_per_coded_sample / 8; |
||||
s->samples_per_block = 4 / avctx->channels; |
||||
s->groups_per_block = 1; |
||||
break; |
||||
case 8: |
||||
/* two groups have all the samples needed */ |
||||
s->block_size = 8 * avctx->bits_per_coded_sample / 8; |
||||
s->samples_per_block = 1; |
||||
s->groups_per_block = 2; |
||||
break; |
||||
default: |
||||
/* need avctx->channels groups */ |
||||
s->block_size = 4 * avctx->channels * |
||||
avctx->bits_per_coded_sample / 8; |
||||
s->samples_per_block = 4; |
||||
s->groups_per_block = avctx->channels; |
||||
break; |
||||
} |
||||
} |
||||
|
||||
if (avctx->debug & FF_DEBUG_PICT_INFO) |
||||
av_dlog(avctx, |
||||
"pcm_dvd_parse_header: %d channels, %d bits per sample, %d Hz, %d bit/s\n", |
||||
avctx->channels, avctx->bits_per_coded_sample, |
||||
avctx->sample_rate, avctx->bit_rate); |
||||
|
||||
s->last_header = header_int; |
||||
|
||||
return 0; |
||||
} |
||||
|
||||
static void *pcm_dvd_decode_samples(AVCodecContext *avctx, const uint8_t *src, |
||||
void *dst, int blocks) |
||||
{ |
||||
PCMDVDContext *s = avctx->priv_data; |
||||
int16_t *dst16 = dst; |
||||
int32_t *dst32 = dst; |
||||
GetByteContext gb; |
||||
int i; |
||||
uint8_t t; |
||||
int samples; |
||||
|
||||
bytestream2_init(&gb, src, blocks * s->block_size); |
||||
switch (avctx->bits_per_coded_sample) { |
||||
case 16: |
||||
#if HAVE_BIGENDIAN |
||||
bytestream2_get_buffer(&gb, dst16, blocks * s->block_size); |
||||
dst16 += blocks * block_size / 2; |
||||
#else |
||||
samples = blocks * avctx->channels; |
||||
do { |
||||
*dst16++ = bytestream2_get_be16u(&gb); |
||||
} while (--samples); |
||||
#endif |
||||
return dst16; |
||||
case 20: |
||||
do { |
||||
for (i = s->groups_per_block; i; i--) { |
||||
dst32[0] = bytestream2_get_be16u(&gb) << 16; |
||||
dst32[1] = bytestream2_get_be16u(&gb) << 16; |
||||
dst32[2] = bytestream2_get_be16u(&gb) << 16; |
||||
dst32[3] = bytestream2_get_be16u(&gb) << 16; |
||||
t = bytestream2_get_byteu(&gb); |
||||
*dst32 += (t & 0xf0) << 8; |
||||
*dst32 += (t & 0x0f) << 12; |
||||
t = bytestream2_get_byteu(&gb); |
||||
*dst32 += (t & 0xf0) << 8; |
||||
*dst32 += (t & 0x0f) << 12; |
||||
} |
||||
} while (--blocks); |
||||
return dst32; |
||||
case 24: |
||||
do { |
||||
for (i = s->groups_per_block; i; i--) { |
||||
dst32[0] = bytestream2_get_be16u(&gb) << 16; |
||||
dst32[1] = bytestream2_get_be16u(&gb) << 16; |
||||
dst32[2] = bytestream2_get_be16u(&gb) << 16; |
||||
dst32[3] = bytestream2_get_be16u(&gb) << 16; |
||||
*dst32++ += bytestream2_get_byteu(&gb) << 8; |
||||
*dst32++ += bytestream2_get_byteu(&gb) << 8; |
||||
*dst32++ += bytestream2_get_byteu(&gb) << 8; |
||||
*dst32++ += bytestream2_get_byteu(&gb) << 8; |
||||
} |
||||
} while (--blocks); |
||||
return dst32; |
||||
default: |
||||
return NULL; |
||||
} |
||||
} |
||||
|
||||
static int pcm_dvd_decode_frame(AVCodecContext *avctx, void *data, |
||||
int *got_frame_ptr, AVPacket *avpkt) |
||||
{ |
||||
AVFrame *frame = data; |
||||
const uint8_t *src = avpkt->data; |
||||
int buf_size = avpkt->size; |
||||
PCMDVDContext *s = avctx->priv_data; |
||||
int retval; |
||||
int blocks; |
||||
void *dst; |
||||
|
||||
if (buf_size < 3) { |
||||
av_log(avctx, AV_LOG_ERROR, "PCM packet too small\n"); |
||||
return AVERROR_INVALIDDATA; |
||||
} |
||||
|
||||
if ((retval = pcm_dvd_parse_header(avctx, src))) |
||||
return retval; |
||||
src += 3; |
||||
buf_size -= 3; |
||||
|
||||
blocks = (buf_size + s->extra_sample_count) / s->block_size; |
||||
|
||||
/* get output buffer */ |
||||
frame->nb_samples = blocks * s->samples_per_block; |
||||
if ((retval = ff_get_buffer(avctx, frame, 0)) < 0) { |
||||
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); |
||||
return retval; |
||||
} |
||||
dst = frame->data[0]; |
||||
|
||||
/* consume leftover samples from last packet */ |
||||
if (s->extra_sample_count) { |
||||
int missing_samples = s->block_size - s->extra_sample_count; |
||||
if (buf_size >= missing_samples) { |
||||
memcpy(s->extra_samples + s->extra_sample_count, src, |
||||
missing_samples); |
||||
dst = pcm_dvd_decode_samples(avctx, s->extra_samples, dst, 1); |
||||
src += missing_samples; |
||||
buf_size -= missing_samples; |
||||
s->extra_sample_count = 0; |
||||
blocks--; |
||||
} else { |
||||
/* new packet still doesn't have enough samples */ |
||||
memcpy(s->extra_samples + s->extra_sample_count, src, buf_size); |
||||
s->extra_sample_count += buf_size; |
||||
return avpkt->size; |
||||
} |
||||
} |
||||
|
||||
/* decode remaining complete samples */ |
||||
if (blocks) { |
||||
pcm_dvd_decode_samples(avctx, src, dst, blocks); |
||||
buf_size -= blocks * s->block_size; |
||||
} |
||||
|
||||
/* store leftover samples */ |
||||
if (buf_size) { |
||||
src += blocks * s->block_size; |
||||
memcpy(s->extra_samples, src, buf_size); |
||||
s->extra_sample_count = buf_size; |
||||
} |
||||
|
||||
*got_frame_ptr = 1; |
||||
|
||||
return avpkt->size; |
||||
} |
||||
|
||||
AVCodec ff_pcm_dvd_decoder = { |
||||
.name = "pcm_dvd", |
||||
.long_name = NULL_IF_CONFIG_SMALL("PCM signed 16|20|24-bit big-endian for DVD media"), |
||||
.type = AVMEDIA_TYPE_AUDIO, |
||||
.id = AV_CODEC_ID_PCM_DVD, |
||||
.priv_data_size = sizeof(PCMDVDContext), |
||||
.init = pcm_dvd_decode_init, |
||||
.decode = pcm_dvd_decode_frame, |
||||
.close = pcm_dvd_decode_uninit, |
||||
.capabilities = CODEC_CAP_DR1, |
||||
.sample_fmts = (const enum AVSampleFormat[]) { |
||||
AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_NONE |
||||
} |
||||
}; |
||||
Loading…
Reference in new issue