1
0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-07 11:13:41 +02:00
FFmpeg/libavcodec/pcm-dvdenc.c
Andreas Rheinhardt a247ac640d avcodec: Constify AVCodecs
Given that the AVCodec.next pointer has now been removed, most of the
AVCodecs are not modified at all any more and can therefore be made
const (as this patch does); the only exceptions are the very few codecs
for external libraries that have a init_static_data callback.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>
2021-04-27 10:43:15 -03:00

193 lines
6.8 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 "avcodec.h"
#include "bytestream.h"
#include "internal.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
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_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;
}
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;
}
avctx->bits_per_coded_sample = 16 + quant * 4;
avctx->block_align = avctx->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->channels * 2;
frame_size = 2008 / s->block_size;
} 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;
}
frame_size = FFALIGN(2008 / s->block_size, s->samples_per_block);
}
s->header[0] = 0x0c;
s->header[1] = (quant << 6) | (freq << 4) | (avctx->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->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_alloc_packet2(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->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, (*src32++) >> 24);
bytestream2_put_byte(&pb, (*src32++) >> 24);
}
} 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, (*src32++) >> 24);
bytestream2_put_byte(&pb, (*src32++) >> 24);
bytestream2_put_byte(&pb, (*src32++) >> 24);
bytestream2_put_byte(&pb, (*src32++) >> 24);
}
} while (--blocks);
}
break;
}
avpkt->pts = frame->pts;
avpkt->size = pkt_size;
avpkt->duration = ff_samples_to_time_base(avctx, frame->nb_samples);
*got_packet_ptr = 1;
return 0;
}
const AVCodec ff_pcm_dvd_encoder = {
.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_encode_init,
.encode2 = pcm_dvd_encode_frame,
.capabilities = AV_CODEC_CAP_SMALL_LAST_FRAME,
.supported_samplerates = (const int[]) { 48000, 96000, 0},
.channel_layouts = (const uint64_t[]) { AV_CH_LAYOUT_MONO,
AV_CH_LAYOUT_STEREO,
AV_CH_LAYOUT_5POINT1,
AV_CH_LAYOUT_7POINT1,
0 },
.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
AV_SAMPLE_FMT_S32,
AV_SAMPLE_FMT_NONE },
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
};