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FFmpeg/libavcodec/pcm-bluray.c
Andreas Rheinhardt 4243da4ff4 avcodec/codec_internal: Use union for FFCodec decode/encode callbacks 
This is possible, because every given FFCodec has to implement
exactly one of these. Doing so decreases sizeof(FFCodec) and
therefore decreases the size of the binary.
Notice that in case of position-independent code the decrease
is in .data.rel.ro, so that this translates to decreased
memory consumption.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-04-05 20:02:37 +02:00

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/*
* LPCM codecs for PCM format found in Blu-ray PCM streams
* Copyright (c) 2009, 2013 Christian Schmidt
*
* 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
* PCM codec for Blu-ray PCM audio tracks
*/
#include "libavutil/channel_layout.h"
#include "avcodec.h"
#include "bytestream.h"
#include "codec_internal.h"
#include "internal.h"
/*
* Channel Mapping according to
* Blu-ray Disc Read-Only Format Version 1
* Part 3: Audio Visual Basic Specifications
* mono M1 X
* stereo L R
* 3/0 L R C X
* 2/1 L R S X
* 3/1 L R C S
* 2/2 L R LS RS
* 3/2 L R C LS RS X
* 3/2+lfe L R C LS RS lfe
* 3/4 L R C LS Rls Rrs RS X
* 3/4+lfe L R C LS Rls Rrs RS lfe
*/
/**
* Parse the header of a LPCM frame read from a Blu-ray MPEG-TS stream
* @param avctx the codec context
* @param header pointer to the first four bytes of the data packet
*/
static int pcm_bluray_parse_header(AVCodecContext *avctx,
const uint8_t *header)
{
static const uint8_t bits_per_samples[4] = { 0, 16, 20, 24 };
static const AVChannelLayout channel_layouts[16] = {
{ 0 }, AV_CHANNEL_LAYOUT_MONO, { 0 },
AV_CHANNEL_LAYOUT_STEREO, AV_CHANNEL_LAYOUT_SURROUND, AV_CHANNEL_LAYOUT_2_1,
AV_CHANNEL_LAYOUT_4POINT0, AV_CHANNEL_LAYOUT_2_2, AV_CHANNEL_LAYOUT_5POINT0,
AV_CHANNEL_LAYOUT_5POINT1, AV_CHANNEL_LAYOUT_7POINT0, AV_CHANNEL_LAYOUT_7POINT1,
{ 0 }, { 0 }, { 0 }, { 0 },
};
uint8_t channel_layout = header[2] >> 4;
if (avctx->debug & FF_DEBUG_PICT_INFO)
ff_dlog(avctx, "pcm_bluray_parse_header: header = %02x%02x%02x%02x\n",
header[0], header[1], header[2], header[3]);
/* get the sample depth and derive the sample format from it */
avctx->bits_per_coded_sample = bits_per_samples[header[3] >> 6];
if (!(avctx->bits_per_coded_sample == 16 || avctx->bits_per_coded_sample == 24)) {
av_log(avctx, AV_LOG_ERROR, "unsupported sample depth (%d)\n", avctx->bits_per_coded_sample);
return AVERROR_INVALIDDATA;
}
avctx->sample_fmt = avctx->bits_per_coded_sample == 16 ? AV_SAMPLE_FMT_S16
: AV_SAMPLE_FMT_S32;
if (avctx->sample_fmt == AV_SAMPLE_FMT_S32)
avctx->bits_per_raw_sample = avctx->bits_per_coded_sample;
/* get the sample rate. Not all values are used. */
switch (header[2] & 0x0f) {
case 1:
avctx->sample_rate = 48000;
break;
case 4:
avctx->sample_rate = 96000;
break;
case 5:
avctx->sample_rate = 192000;
break;
default:
avctx->sample_rate = 0;
av_log(avctx, AV_LOG_ERROR, "reserved sample rate (%d)\n",
header[2] & 0x0f);
return AVERROR_INVALIDDATA;
}
/*
* get the channel number (and mapping). Not all values are used.
* It must be noted that the number of channels in the MPEG stream can
* differ from the actual meaningful number, e.g. mono audio still has two
* channels, one being empty.
*/
av_channel_layout_uninit(&avctx->ch_layout);
avctx->ch_layout = channel_layouts[channel_layout];
if (!avctx->ch_layout.nb_channels) {
av_log(avctx, AV_LOG_ERROR, "reserved channel configuration (%d)\n",
channel_layout);
return AVERROR_INVALIDDATA;
}
avctx->bit_rate = FFALIGN(avctx->ch_layout.nb_channels, 2) * avctx->sample_rate *
avctx->bits_per_coded_sample;
if (avctx->debug & FF_DEBUG_PICT_INFO)
ff_dlog(avctx,
"pcm_bluray_parse_header: %d channels, %d bits per sample, %d Hz, %"PRId64" bit/s\n",
avctx->ch_layout.nb_channels, avctx->bits_per_coded_sample,
avctx->sample_rate, avctx->bit_rate);
return 0;
}
static int pcm_bluray_decode_frame(AVCodecContext *avctx, AVFrame *frame,
int *got_frame_ptr, AVPacket *avpkt)
{
const uint8_t *src = avpkt->data;
int buf_size = avpkt->size;
GetByteContext gb;
int num_source_channels, channel, retval;
int sample_size, samples;
int16_t *dst16;
int32_t *dst32;
if (buf_size < 4) {
av_log(avctx, AV_LOG_ERROR, "PCM packet too small\n");
return AVERROR_INVALIDDATA;
}
if ((retval = pcm_bluray_parse_header(avctx, src)))
return retval;
src += 4;
buf_size -= 4;
bytestream2_init(&gb, src, buf_size);
/* There's always an even number of channels in the source */
num_source_channels = FFALIGN(avctx->ch_layout.nb_channels, 2);
sample_size = (num_source_channels *
(avctx->sample_fmt == AV_SAMPLE_FMT_S16 ? 16 : 24)) >> 3;
samples = buf_size / sample_size;
/* get output buffer */
frame->nb_samples = samples;
if ((retval = ff_get_buffer(avctx, frame, 0)) < 0)
return retval;
dst16 = (int16_t *)frame->data[0];
dst32 = (int32_t *)frame->data[0];
if (samples) {
switch (avctx->ch_layout.u.mask) {
/* cases with same number of source and coded channels */
case AV_CH_LAYOUT_STEREO:
case AV_CH_LAYOUT_4POINT0:
case AV_CH_LAYOUT_2_2:
samples *= num_source_channels;
if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
#if HAVE_BIGENDIAN
bytestream2_get_buffer(&gb, dst16, buf_size);
#else
do {
*dst16++ = bytestream2_get_be16u(&gb);
} while (--samples);
#endif
} else {
do {
*dst32++ = bytestream2_get_be24u(&gb) << 8;
} while (--samples);
}
break;
/* cases where number of source channels = coded channels + 1 */
case AV_CH_LAYOUT_MONO:
case AV_CH_LAYOUT_SURROUND:
case AV_CH_LAYOUT_2_1:
case AV_CH_LAYOUT_5POINT0:
if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
do {
#if HAVE_BIGENDIAN
bytestream2_get_buffer(&gb, dst16, avctx->ch_layout.nb_channels * 2);
dst16 += avctx->ch_layout.nb_channels;
#else
channel = avctx->ch_layout.nb_channels;
do {
*dst16++ = bytestream2_get_be16u(&gb);
} while (--channel);
#endif
bytestream2_skip(&gb, 2);
} while (--samples);
} else {
do {
channel = avctx->ch_layout.nb_channels;
do {
*dst32++ = bytestream2_get_be24u(&gb) << 8;
} while (--channel);
bytestream2_skip(&gb, 3);
} while (--samples);
}
break;
/* remapping: L, R, C, LBack, RBack, LF */
case AV_CH_LAYOUT_5POINT1:
if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
do {
dst16[0] = bytestream2_get_be16u(&gb);
dst16[1] = bytestream2_get_be16u(&gb);
dst16[2] = bytestream2_get_be16u(&gb);
dst16[4] = bytestream2_get_be16u(&gb);
dst16[5] = bytestream2_get_be16u(&gb);
dst16[3] = bytestream2_get_be16u(&gb);
dst16 += 6;
} while (--samples);
} else {
do {
dst32[0] = bytestream2_get_be24u(&gb) << 8;
dst32[1] = bytestream2_get_be24u(&gb) << 8;
dst32[2] = bytestream2_get_be24u(&gb) << 8;
dst32[4] = bytestream2_get_be24u(&gb) << 8;
dst32[5] = bytestream2_get_be24u(&gb) << 8;
dst32[3] = bytestream2_get_be24u(&gb) << 8;
dst32 += 6;
} while (--samples);
}
break;
/* remapping: L, R, C, LSide, LBack, RBack, RSide, <unused> */
case AV_CH_LAYOUT_7POINT0:
if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
do {
dst16[0] = bytestream2_get_be16u(&gb);
dst16[1] = bytestream2_get_be16u(&gb);
dst16[2] = bytestream2_get_be16u(&gb);
dst16[5] = bytestream2_get_be16u(&gb);
dst16[3] = bytestream2_get_be16u(&gb);
dst16[4] = bytestream2_get_be16u(&gb);
dst16[6] = bytestream2_get_be16u(&gb);
dst16 += 7;
bytestream2_skip(&gb, 2);
} while (--samples);
} else {
do {
dst32[0] = bytestream2_get_be24u(&gb) << 8;
dst32[1] = bytestream2_get_be24u(&gb) << 8;
dst32[2] = bytestream2_get_be24u(&gb) << 8;
dst32[5] = bytestream2_get_be24u(&gb) << 8;
dst32[3] = bytestream2_get_be24u(&gb) << 8;
dst32[4] = bytestream2_get_be24u(&gb) << 8;
dst32[6] = bytestream2_get_be24u(&gb) << 8;
dst32 += 7;
bytestream2_skip(&gb, 3);
} while (--samples);
}
break;
/* remapping: L, R, C, LSide, LBack, RBack, RSide, LF */
case AV_CH_LAYOUT_7POINT1:
if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
do {
dst16[0] = bytestream2_get_be16u(&gb);
dst16[1] = bytestream2_get_be16u(&gb);
dst16[2] = bytestream2_get_be16u(&gb);
dst16[6] = bytestream2_get_be16u(&gb);
dst16[4] = bytestream2_get_be16u(&gb);
dst16[5] = bytestream2_get_be16u(&gb);
dst16[7] = bytestream2_get_be16u(&gb);
dst16[3] = bytestream2_get_be16u(&gb);
dst16 += 8;
} while (--samples);
} else {
do {
dst32[0] = bytestream2_get_be24u(&gb) << 8;
dst32[1] = bytestream2_get_be24u(&gb) << 8;
dst32[2] = bytestream2_get_be24u(&gb) << 8;
dst32[6] = bytestream2_get_be24u(&gb) << 8;
dst32[4] = bytestream2_get_be24u(&gb) << 8;
dst32[5] = bytestream2_get_be24u(&gb) << 8;
dst32[7] = bytestream2_get_be24u(&gb) << 8;
dst32[3] = bytestream2_get_be24u(&gb) << 8;
dst32 += 8;
} while (--samples);
}
break;
}
}
*got_frame_ptr = 1;
retval = bytestream2_tell(&gb);
if (avctx->debug & FF_DEBUG_BITSTREAM)
ff_dlog(avctx, "pcm_bluray_decode_frame: decoded %d -> %d bytes\n",
retval, buf_size);
return retval + 4;
}
const FFCodec ff_pcm_bluray_decoder = {
.p.name = "pcm_bluray",
.p.long_name = NULL_IF_CONFIG_SMALL("PCM signed 16|20|24-bit big-endian for Blu-ray media"),
.p.type = AVMEDIA_TYPE_AUDIO,
.p.id = AV_CODEC_ID_PCM_BLURAY,
FF_CODEC_DECODE_CB(pcm_bluray_decode_frame),
.p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
.p.sample_fmts = (const enum AVSampleFormat[]){
AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_NONE
},
};
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