mirror of
https://gitee.com/openharmony/third_party_ffmpeg
synced 2024-11-23 19:30:05 +00:00
a16577d985
This is essentially a MS GSM decoder extension that supports more sampling rates and lower bitrates. Signed-off-by: Anton Khirnov <anton@khirnov.net>
138 lines
4.1 KiB
C
138 lines
4.1 KiB
C
/*
|
|
* gsm 06.10 decoder
|
|
* Copyright (c) 2010 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
|
|
*
|
|
* 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
|
|
* GSM decoder
|
|
*/
|
|
|
|
#include "libavutil/channel_layout.h"
|
|
#include "avcodec.h"
|
|
#include "get_bits.h"
|
|
#include "internal.h"
|
|
#include "msgsmdec.h"
|
|
|
|
#include "gsmdec_template.c"
|
|
|
|
static av_cold int gsm_init(AVCodecContext *avctx)
|
|
{
|
|
avctx->channels = 1;
|
|
avctx->channel_layout = AV_CH_LAYOUT_MONO;
|
|
if (!avctx->sample_rate)
|
|
avctx->sample_rate = 8000;
|
|
avctx->sample_fmt = AV_SAMPLE_FMT_S16;
|
|
|
|
switch (avctx->codec_id) {
|
|
case AV_CODEC_ID_GSM:
|
|
avctx->frame_size = GSM_FRAME_SIZE;
|
|
avctx->block_align = GSM_BLOCK_SIZE;
|
|
break;
|
|
case AV_CODEC_ID_GSM_MS:
|
|
avctx->frame_size = 2 * GSM_FRAME_SIZE;
|
|
if (!avctx->block_align)
|
|
avctx->block_align = GSM_MS_BLOCK_SIZE;
|
|
else
|
|
if (avctx->block_align < MSN_MIN_BLOCK_SIZE ||
|
|
avctx->block_align > GSM_MS_BLOCK_SIZE ||
|
|
(avctx->block_align - MSN_MIN_BLOCK_SIZE) % 3) {
|
|
av_log(avctx, AV_LOG_ERROR, "Invalid block alignment %d\n",
|
|
avctx->block_align);
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int gsm_decode_frame(AVCodecContext *avctx, void *data,
|
|
int *got_frame_ptr, AVPacket *avpkt)
|
|
{
|
|
AVFrame *frame = data;
|
|
int res;
|
|
GetBitContext gb;
|
|
const uint8_t *buf = avpkt->data;
|
|
int buf_size = avpkt->size;
|
|
int16_t *samples;
|
|
|
|
if (buf_size < avctx->block_align) {
|
|
av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
|
|
/* get output buffer */
|
|
frame->nb_samples = avctx->frame_size;
|
|
if ((res = ff_get_buffer(avctx, frame, 0)) < 0) {
|
|
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
|
|
return res;
|
|
}
|
|
samples = (int16_t *)frame->data[0];
|
|
|
|
switch (avctx->codec_id) {
|
|
case AV_CODEC_ID_GSM:
|
|
init_get_bits(&gb, buf, buf_size * 8);
|
|
if (get_bits(&gb, 4) != 0xd)
|
|
av_log(avctx, AV_LOG_WARNING, "Missing GSM magic!\n");
|
|
res = gsm_decode_block(avctx, samples, &gb, GSM_13000);
|
|
if (res < 0)
|
|
return res;
|
|
break;
|
|
case AV_CODEC_ID_GSM_MS:
|
|
res = ff_msgsm_decode_block(avctx, samples, buf,
|
|
(GSM_MS_BLOCK_SIZE - avctx->block_align) / 3);
|
|
if (res < 0)
|
|
return res;
|
|
}
|
|
|
|
*got_frame_ptr = 1;
|
|
|
|
return avctx->block_align;
|
|
}
|
|
|
|
static void gsm_flush(AVCodecContext *avctx)
|
|
{
|
|
GSMContext *s = avctx->priv_data;
|
|
memset(s, 0, sizeof(*s));
|
|
}
|
|
|
|
AVCodec ff_gsm_decoder = {
|
|
.name = "gsm",
|
|
.long_name = NULL_IF_CONFIG_SMALL("GSM"),
|
|
.type = AVMEDIA_TYPE_AUDIO,
|
|
.id = AV_CODEC_ID_GSM,
|
|
.priv_data_size = sizeof(GSMContext),
|
|
.init = gsm_init,
|
|
.decode = gsm_decode_frame,
|
|
.flush = gsm_flush,
|
|
.capabilities = CODEC_CAP_DR1,
|
|
};
|
|
|
|
AVCodec ff_gsm_ms_decoder = {
|
|
.name = "gsm_ms",
|
|
.long_name = NULL_IF_CONFIG_SMALL("GSM Microsoft variant"),
|
|
.type = AVMEDIA_TYPE_AUDIO,
|
|
.id = AV_CODEC_ID_GSM_MS,
|
|
.priv_data_size = sizeof(GSMContext),
|
|
.init = gsm_init,
|
|
.decode = gsm_decode_frame,
|
|
.flush = gsm_flush,
|
|
.capabilities = CODEC_CAP_DR1,
|
|
};
|