110 lines
2.8 KiB
C
110 lines
2.8 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 "avcodec.h"
|
|
#include "get_bits.h"
|
|
#include "msgsmdec.h"
|
|
|
|
#include "gsmdec_template.c"
|
|
|
|
static av_cold int gsm_init(AVCodecContext *avctx)
|
|
{
|
|
avctx->channels = 1;
|
|
if (!avctx->sample_rate)
|
|
avctx->sample_rate = 8000;
|
|
avctx->sample_fmt = AV_SAMPLE_FMT_S16;
|
|
|
|
switch (avctx->codec_id) {
|
|
case CODEC_ID_GSM:
|
|
avctx->frame_size = GSM_FRAME_SIZE;
|
|
avctx->block_align = GSM_BLOCK_SIZE;
|
|
break;
|
|
case CODEC_ID_GSM_MS:
|
|
avctx->frame_size = 2 * GSM_FRAME_SIZE;
|
|
avctx->block_align = GSM_MS_BLOCK_SIZE;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int gsm_decode_frame(AVCodecContext *avctx, void *data,
|
|
int *data_size, AVPacket *avpkt)
|
|
{
|
|
int res;
|
|
GetBitContext gb;
|
|
const uint8_t *buf = avpkt->data;
|
|
int buf_size = avpkt->size;
|
|
int16_t *samples = data;
|
|
int frame_bytes = 2 * avctx->frame_size;
|
|
|
|
if (*data_size < frame_bytes)
|
|
return -1;
|
|
*data_size = 0;
|
|
if(buf_size < avctx->block_align)
|
|
return AVERROR_INVALIDDATA;
|
|
|
|
switch (avctx->codec_id) {
|
|
case 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);
|
|
if (res < 0)
|
|
return res;
|
|
break;
|
|
case CODEC_ID_GSM_MS:
|
|
res = ff_msgsm_decode_block(avctx, samples, buf);
|
|
if (res < 0)
|
|
return res;
|
|
}
|
|
*data_size = frame_bytes;
|
|
return avctx->block_align;
|
|
}
|
|
|
|
AVCodec ff_gsm_decoder = {
|
|
"gsm",
|
|
AVMEDIA_TYPE_AUDIO,
|
|
CODEC_ID_GSM,
|
|
sizeof(GSMContext),
|
|
gsm_init,
|
|
NULL,
|
|
NULL,
|
|
gsm_decode_frame,
|
|
.long_name = NULL_IF_CONFIG_SMALL("GSM"),
|
|
};
|
|
|
|
AVCodec ff_gsm_ms_decoder = {
|
|
"gsm_ms",
|
|
AVMEDIA_TYPE_AUDIO,
|
|
CODEC_ID_GSM_MS,
|
|
sizeof(GSMContext),
|
|
gsm_init,
|
|
NULL,
|
|
NULL,
|
|
gsm_decode_frame,
|
|
.long_name = NULL_IF_CONFIG_SMALL("GSM Microsoft variant"),
|
|
};
|