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/*
* Xiph CELT decoder using libcelt
* Copyright (c) 2011 Nicolas George
*
* 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 <celt/celt.h>
#include <celt/celt_header.h>
#include "avcodec.h"
#include "libavutil/intreadwrite.h"
struct libcelt_context {
CELTMode *mode;
CELTDecoder *dec;
AVFrame frame;
int discard;
};
static int ff_celt_error_to_averror(int err)
{
switch (err) {
case CELT_BAD_ARG: return AVERROR(EINVAL);
#ifdef CELT_BUFFER_TOO_SMALL
case CELT_BUFFER_TOO_SMALL: return AVERROR(ENOBUFS);
#endif
case CELT_INTERNAL_ERROR: return AVERROR(EFAULT);
case CELT_CORRUPTED_DATA: return AVERROR_INVALIDDATA;
case CELT_UNIMPLEMENTED: return AVERROR(ENOSYS);
#ifdef ENOTRECOVERABLE
case CELT_INVALID_STATE: return AVERROR(ENOTRECOVERABLE);
#endif
case CELT_ALLOC_FAIL: return AVERROR(ENOMEM);
default: return AVERROR(EINVAL);
}
}
static int ff_celt_bitstream_version_hack(CELTMode *mode)
{
CELTHeader header = { .version_id = 0 };
celt_header_init(&header, mode, 960, 2);
return header.version_id;
}
static av_cold int libcelt_dec_init(AVCodecContext *c)
{
struct libcelt_context *celt = c->priv_data;
int err;
if (!c->channels || !c->frame_size ||
c->frame_size > INT_MAX / sizeof(int16_t) / c->channels)
return AVERROR(EINVAL);
celt->mode = celt_mode_create(c->sample_rate, c->frame_size, &err);
if (!celt->mode)
return ff_celt_error_to_averror(err);
celt->dec = celt_decoder_create_custom(celt->mode, c->channels, &err);
if (!celt->dec) {
celt_mode_destroy(celt->mode);
return ff_celt_error_to_averror(err);
}
if (c->extradata_size >= 4) {
celt->discard = AV_RL32(c->extradata);
if (celt->discard < 0 || celt->discard >= c->frame_size) {
av_log(c, AV_LOG_WARNING,
"Invalid overlap (%d), ignored.\n", celt->discard);
celt->discard = 0;
}
}
if (c->extradata_size >= 8) {
unsigned version = AV_RL32(c->extradata + 4);
unsigned lib_version = ff_celt_bitstream_version_hack(celt->mode);
if (version != lib_version)
av_log(c, AV_LOG_WARNING,
"CELT bitstream version 0x%x may be "
"improperly decoded by libcelt for version 0x%x.\n",
version, lib_version);
}
c->sample_fmt = AV_SAMPLE_FMT_S16;
avcodec_get_frame_defaults(&celt->frame);
c->coded_frame = &celt->frame;
return 0;
}
static av_cold int libcelt_dec_close(AVCodecContext *c)
{
struct libcelt_context *celt = c->priv_data;
celt_decoder_destroy(celt->dec);
celt_mode_destroy(celt->mode);
return 0;
}
static int libcelt_dec_decode(AVCodecContext *c, void *frame,
int *got_frame_ptr, AVPacket *pkt)
{
struct libcelt_context *celt = c->priv_data;
int err;
int16_t *pcm;
celt->frame.nb_samples = c->frame_size;
err = c->get_buffer(c, &celt->frame);
if (err < 0) {
av_log(c, AV_LOG_ERROR, "get_buffer() failed\n");
return err;
}
pcm = (int16_t *)celt->frame.data[0];
err = celt_decode(celt->dec, pkt->data, pkt->size, pcm, c->frame_size);
if (err < 0)
return ff_celt_error_to_averror(err);
if (celt->discard) {
celt->frame.nb_samples -= celt->discard;
memmove(pcm, pcm + celt->discard * c->channels,
celt->frame.nb_samples * c->channels * sizeof(int16_t));
celt->discard = 0;
}
*got_frame_ptr = 1;
*(AVFrame *)frame = celt->frame;
return pkt->size;
}
AVCodec ff_libcelt_decoder = {
.name = "libcelt",
.type = AVMEDIA_TYPE_AUDIO,
.id = AV_CODEC_ID_CELT,
.priv_data_size = sizeof(struct libcelt_context),
.init = libcelt_dec_init,
.close = libcelt_dec_close,
.decode = libcelt_dec_decode,
.capabilities = CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("Xiph CELT decoder using libcelt"),
};
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