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/*
* 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 "msgsmdec.h"
#include "gsmdec_template.c"
static av_cold int gsm_init(AVCodecContext *avctx)
{
GSMContext *s = avctx->priv_data;
avctx->channels = 1;
avctx->channel_layout = AV_CH_LAYOUT_MONO;
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;
avctx->block_align = GSM_MS_BLOCK_SIZE;
}
avcodec_get_frame_defaults(&s->frame);
avctx->coded_frame = &s->frame;
return 0;
}
static int gsm_decode_frame(AVCodecContext *avctx, void *data,
int *got_frame_ptr, AVPacket *avpkt)
{
GSMContext *s = avctx->priv_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 */
s->frame.nb_samples = avctx->frame_size;
if ((res = avctx->get_buffer(avctx, &s->frame)) < 0) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return res;
}
samples = (int16_t *)s->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);
if (res < 0)
return res;
break;
case AV_CODEC_ID_GSM_MS:
res = ff_msgsm_decode_block(avctx, samples, buf);
if (res < 0)
return res;
}
*got_frame_ptr = 1;
*(AVFrame *)data = s->frame;
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",
.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,
.long_name = NULL_IF_CONFIG_SMALL("GSM"),
};
AVCodec ff_gsm_ms_decoder = {
.name = "gsm_ms",
.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,
.long_name = NULL_IF_CONFIG_SMALL("GSM Microsoft variant"),
};
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