ffmpeg/libavcodec/libspeexdec.c

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/*
* Copyright (C) 2008 David Conrad
*
* 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 <speex/speex.h>
#include <speex/speex_header.h>
#include <speex/speex_stereo.h>
#include <speex/speex_callbacks.h>
typedef struct {
SpeexBits bits;
SpeexStereoState stereo;
void *dec_state;
SpeexHeader *header;
} LibSpeexContext;
static av_cold int libspeex_decode_init(AVCodecContext *avctx)
{
LibSpeexContext *s = avctx->priv_data;
const SpeexMode *mode;
// defaults in the case of a missing header
if (avctx->sample_rate <= 8000)
mode = &speex_nb_mode;
else if (avctx->sample_rate <= 16000)
mode = &speex_wb_mode;
else
mode = &speex_uwb_mode;
if (avctx->extradata_size >= 80)
s->header = speex_packet_to_header(avctx->extradata, avctx->extradata_size);
avctx->sample_fmt = SAMPLE_FMT_S16;
if (s->header) {
avctx->sample_rate = s->header->rate;
avctx->channels = s->header->nb_channels;
avctx->frame_size = s->header->frame_size;
mode = speex_lib_get_mode(s->header->mode);
if (!mode) {
av_log(avctx, AV_LOG_ERROR, "Unknown Speex mode %d", s->header->mode);
return -1;
}
} else
av_log(avctx, AV_LOG_INFO, "Missing speex header, assuming defaults\n");
if (avctx->channels > 2) {
av_log(avctx, AV_LOG_ERROR, "Only stereo and mono supported\n");
return -1;
}
speex_bits_init(&s->bits);
s->dec_state = speex_decoder_init(mode);
if (!s->dec_state) {
av_log(avctx, AV_LOG_ERROR, "Error initializing libspeex decoder\n");
return -1;
}
if (!s->header)
speex_decoder_ctl(s->dec_state, SPEEX_GET_FRAME_SIZE, &avctx->frame_size);
if (avctx->channels == 2) {
SpeexCallback callback;
callback.callback_id = SPEEX_INBAND_STEREO;
callback.func = speex_std_stereo_request_handler;
callback.data = &s->stereo;
s->stereo = (SpeexStereoState)SPEEX_STEREO_STATE_INIT;
speex_decoder_ctl(s->dec_state, SPEEX_SET_HANDLER, &callback);
}
return 0;
}
static int libspeex_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
const uint8_t *buf, int buf_size)
{
LibSpeexContext *s = avctx->priv_data;
int16_t *output = data, *end;
int i, num_samples;
num_samples = avctx->frame_size * avctx->channels;
end = output + *data_size/2;
speex_bits_read_from(&s->bits, buf, buf_size);
for (i = 0; speex_bits_remaining(&s->bits) && output + num_samples < end; i++) {
int ret = speex_decode_int(s->dec_state, &s->bits, output);
if (ret <= -2) {
av_log(avctx, AV_LOG_ERROR, "Error decoding speex frame\n");
return -1;
} else if (ret == -1)
// end of stream
break;
if (avctx->channels == 2)
speex_decode_stereo_int(output, avctx->frame_size, &s->stereo);
output += num_samples;
}
*data_size = i * avctx->channels * avctx->frame_size * 2;
return buf_size;
}
static av_cold int libspeex_decode_close(AVCodecContext *avctx)
{
LibSpeexContext *s = avctx->priv_data;
speex_header_free(s->header);
speex_bits_destroy(&s->bits);
speex_decoder_destroy(s->dec_state);
return 0;
}
AVCodec libspeex_decoder = {
"libspeex",
CODEC_TYPE_AUDIO,
CODEC_ID_SPEEX,
sizeof(LibSpeexContext),
libspeex_decode_init,
NULL,
libspeex_decode_close,
libspeex_decode_frame,
.long_name = NULL_IF_CONFIG_SMALL("libspeex"),
};