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FFmpeg/libavcodec/libgsmdec.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

156 lines
4.5 KiB
C

/*
* Interface to libgsm for GSM decoding
* Copyright (c) 2005 Alban Bedel <albeu@free.fr>
* Copyright (c) 2006, 2007 Michel Bardiaux <mbardiaux@mediaxim.be>
*
* 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
*/
/**
* @file
* Interface to libgsm for GSM decoding
*/
// The idiosyncrasies of GSM-in-WAV are explained at http://kbs.cs.tu-berlin.de/~jutta/toast.html
#include "config.h"
#if HAVE_GSM_H
#include <gsm.h>
#else
#include <gsm/gsm.h>
#endif
#include "libavutil/channel_layout.h"
#include "libavutil/common.h"
#include "avcodec.h"
#include "internal.h"
#include "gsm.h"
typedef struct LibGSMDecodeContext {
struct gsm_state *state;
} LibGSMDecodeContext;
static av_cold int libgsm_decode_init(AVCodecContext *avctx) {
LibGSMDecodeContext *s = avctx->priv_data;
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;
s->state = gsm_create();
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: {
int one = 1;
gsm_option(s->state, GSM_OPT_WAV49, &one);
avctx->frame_size = 2 * GSM_FRAME_SIZE;
avctx->block_align = GSM_MS_BLOCK_SIZE;
}
}
return 0;
}
static av_cold int libgsm_decode_close(AVCodecContext *avctx) {
LibGSMDecodeContext *s = avctx->priv_data;
gsm_destroy(s->state);
s->state = NULL;
return 0;
}
static int libgsm_decode_frame(AVCodecContext *avctx, void *data,
int *got_frame_ptr, AVPacket *avpkt)
{
int i, ret;
LibGSMDecodeContext *s = avctx->priv_data;
AVFrame *frame = data;
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 ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
return ret;
samples = (int16_t *)frame->data[0];
for (i = 0; i < avctx->frame_size / GSM_FRAME_SIZE; i++) {
if ((ret = gsm_decode(s->state, buf, samples)) < 0)
return -1;
buf += GSM_BLOCK_SIZE;
samples += GSM_FRAME_SIZE;
}
*got_frame_ptr = 1;
return avctx->block_align;
}
static void libgsm_flush(AVCodecContext *avctx) {
LibGSMDecodeContext *s = avctx->priv_data;
int one = 1;
gsm_destroy(s->state);
s->state = gsm_create();
if (avctx->codec_id == AV_CODEC_ID_GSM_MS)
gsm_option(s->state, GSM_OPT_WAV49, &one);
}
#if CONFIG_LIBGSM_DECODER
const AVCodec ff_libgsm_decoder = {
.name = "libgsm",
.long_name = NULL_IF_CONFIG_SMALL("libgsm GSM"),
.type = AVMEDIA_TYPE_AUDIO,
.id = AV_CODEC_ID_GSM,
.priv_data_size = sizeof(LibGSMDecodeContext),
.init = libgsm_decode_init,
.close = libgsm_decode_close,
.decode = libgsm_decode_frame,
.flush = libgsm_flush,
.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
.wrapper_name = "libgsm",
};
#endif
#if CONFIG_LIBGSM_MS_DECODER
const AVCodec ff_libgsm_ms_decoder = {
.name = "libgsm_ms",
.long_name = NULL_IF_CONFIG_SMALL("libgsm GSM Microsoft variant"),
.type = AVMEDIA_TYPE_AUDIO,
.id = AV_CODEC_ID_GSM_MS,
.priv_data_size = sizeof(LibGSMDecodeContext),
.init = libgsm_decode_init,
.close = libgsm_decode_close,
.decode = libgsm_decode_frame,
.flush = libgsm_flush,
.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
.wrapper_name = "libgsm",
};
#endif