mirror of https://git.ffmpeg.org/ffmpeg.git
194 lines
6.9 KiB
C
194 lines
6.9 KiB
C
/*
|
|
* LPCM codecs for PCM formats found in Video DVD streams
|
|
* Copyright (c) 2018 Paul B Mahol
|
|
*
|
|
* 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/channel_layout.h"
|
|
#include "avcodec.h"
|
|
#include "bytestream.h"
|
|
#include "codec_internal.h"
|
|
#include "encode.h"
|
|
|
|
typedef struct PCMDVDContext {
|
|
uint8_t header[3]; // Header added to every frame
|
|
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 20/24-bit sample groups per block
|
|
} PCMDVDContext;
|
|
|
|
static av_cold int pcm_dvd_encode_init(AVCodecContext *avctx)
|
|
{
|
|
PCMDVDContext *s = avctx->priv_data;
|
|
int quant, freq, frame_size;
|
|
|
|
switch (avctx->sample_rate) {
|
|
case 48000:
|
|
freq = 0;
|
|
break;
|
|
case 96000:
|
|
freq = 1;
|
|
break;
|
|
default:
|
|
av_assert1(0);
|
|
}
|
|
|
|
switch (avctx->sample_fmt) {
|
|
case AV_SAMPLE_FMT_S16:
|
|
avctx->bits_per_coded_sample = 16;
|
|
quant = 0;
|
|
break;
|
|
case AV_SAMPLE_FMT_S32:
|
|
avctx->bits_per_coded_sample = 24;
|
|
quant = 2;
|
|
break;
|
|
default:
|
|
av_assert1(0);
|
|
}
|
|
|
|
avctx->bits_per_coded_sample = 16 + quant * 4;
|
|
avctx->block_align = avctx->ch_layout.nb_channels * avctx->bits_per_coded_sample / 8;
|
|
avctx->bit_rate = avctx->block_align * 8LL * avctx->sample_rate;
|
|
if (avctx->bit_rate > 9800000) {
|
|
av_log(avctx, AV_LOG_ERROR, "Too big bitrate: reduce sample rate, bitdepth or channels.\n");
|
|
return AVERROR(EINVAL);
|
|
}
|
|
|
|
if (avctx->sample_fmt == AV_SAMPLE_FMT_S16) {
|
|
s->samples_per_block = 1;
|
|
s->block_size = avctx->ch_layout.nb_channels * 2;
|
|
frame_size = 2008 / s->block_size;
|
|
} else {
|
|
switch (avctx->ch_layout.nb_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->ch_layout.nb_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->ch_layout.nb_channels groups */
|
|
s->block_size = 4 * avctx->ch_layout.nb_channels *
|
|
avctx->bits_per_coded_sample / 8;
|
|
s->samples_per_block = 4;
|
|
s->groups_per_block = avctx->ch_layout.nb_channels;
|
|
break;
|
|
}
|
|
|
|
frame_size = FFALIGN(2008 / s->block_size, s->samples_per_block);
|
|
}
|
|
|
|
s->header[0] = 0x0c;
|
|
s->header[1] = (quant << 6) | (freq << 4) | (avctx->ch_layout.nb_channels - 1);
|
|
s->header[2] = 0x80;
|
|
|
|
if (!avctx->frame_size)
|
|
avctx->frame_size = frame_size;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pcm_dvd_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
|
|
const AVFrame *frame, int *got_packet_ptr)
|
|
{
|
|
PCMDVDContext *s = avctx->priv_data;
|
|
int samples = frame->nb_samples * avctx->ch_layout.nb_channels;
|
|
int64_t pkt_size = (frame->nb_samples / s->samples_per_block) * s->block_size + 3;
|
|
int blocks = (pkt_size - 3) / s->block_size;
|
|
const int16_t *src16;
|
|
const int32_t *src32;
|
|
PutByteContext pb;
|
|
int ret;
|
|
|
|
if ((ret = ff_get_encode_buffer(avctx, avpkt, pkt_size, 0)) < 0)
|
|
return ret;
|
|
|
|
memcpy(avpkt->data, s->header, 3);
|
|
|
|
src16 = (const int16_t *)frame->data[0];
|
|
src32 = (const int32_t *)frame->data[0];
|
|
|
|
bytestream2_init_writer(&pb, avpkt->data + 3, avpkt->size - 3);
|
|
|
|
switch (avctx->sample_fmt) {
|
|
case AV_SAMPLE_FMT_S16:
|
|
do {
|
|
bytestream2_put_be16(&pb, *src16++);
|
|
} while (--samples);
|
|
break;
|
|
case AV_SAMPLE_FMT_S32:
|
|
if (avctx->ch_layout.nb_channels == 1) {
|
|
do {
|
|
for (int i = 2; i; i--) {
|
|
bytestream2_put_be16(&pb, src32[0] >> 16);
|
|
bytestream2_put_be16(&pb, src32[1] >> 16);
|
|
bytestream2_put_byte(&pb, (uint8_t)((*src32++) >> 8));
|
|
bytestream2_put_byte(&pb, (uint8_t)((*src32++) >> 8));
|
|
}
|
|
} while (--blocks);
|
|
} else {
|
|
do {
|
|
for (int i = s->groups_per_block; i; i--) {
|
|
bytestream2_put_be16(&pb, src32[0] >> 16);
|
|
bytestream2_put_be16(&pb, src32[1] >> 16);
|
|
bytestream2_put_be16(&pb, src32[2] >> 16);
|
|
bytestream2_put_be16(&pb, src32[3] >> 16);
|
|
bytestream2_put_byte(&pb, (uint8_t)((*src32++) >> 8));
|
|
bytestream2_put_byte(&pb, (uint8_t)((*src32++) >> 8));
|
|
bytestream2_put_byte(&pb, (uint8_t)((*src32++) >> 8));
|
|
bytestream2_put_byte(&pb, (uint8_t)((*src32++) >> 8));
|
|
}
|
|
} while (--blocks);
|
|
}
|
|
break;
|
|
}
|
|
|
|
*got_packet_ptr = 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
const FFCodec ff_pcm_dvd_encoder = {
|
|
.p.name = "pcm_dvd",
|
|
CODEC_LONG_NAME("PCM signed 16|20|24-bit big-endian for DVD media"),
|
|
.p.type = AVMEDIA_TYPE_AUDIO,
|
|
.p.id = AV_CODEC_ID_PCM_DVD,
|
|
.p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_SMALL_LAST_FRAME |
|
|
AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE,
|
|
.priv_data_size = sizeof(PCMDVDContext),
|
|
.init = pcm_dvd_encode_init,
|
|
FF_CODEC_ENCODE_CB(pcm_dvd_encode_frame),
|
|
.p.supported_samplerates = (const int[]) { 48000, 96000, 0},
|
|
.p.ch_layouts = (const AVChannelLayout[]) { AV_CHANNEL_LAYOUT_MONO,
|
|
AV_CHANNEL_LAYOUT_STEREO,
|
|
AV_CHANNEL_LAYOUT_5POINT1,
|
|
AV_CHANNEL_LAYOUT_7POINT1,
|
|
{ 0 } },
|
|
.p.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
|
|
AV_SAMPLE_FMT_S32,
|
|
AV_SAMPLE_FMT_NONE },
|
|
};
|