ffmpeg/libavcodec/pafaudio.c

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/*
* Packed Animation File audio decoder
* Copyright (c) 2012 Paul B Mahol
*
* 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 "libavutil/intreadwrite.h"
#include "avcodec.h"
#include "internal.h"
#include "mathops.h"
#define PAF_SOUND_SAMPLES 2205
#define PAF_SOUND_FRAME_SIZE ((256 + PAF_SOUND_SAMPLES) * 2)
static av_cold int paf_audio_init(AVCodecContext *avctx)
{
if (avctx->channels != 2) {
av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n");
return AVERROR_INVALIDDATA;
}
avctx->channel_layout = AV_CH_LAYOUT_STEREO;
avctx->sample_fmt = AV_SAMPLE_FMT_S16;
return 0;
}
static int paf_audio_decode(AVCodecContext *avctx, void *data,
int *got_frame, AVPacket *pkt)
{
AVFrame *frame = data;
int16_t *output_samples;
const uint8_t *src = pkt->data;
int frames, ret, i, j;
int16_t cb[256];
frames = pkt->size / PAF_SOUND_FRAME_SIZE;
if (frames < 1)
return AVERROR_INVALIDDATA;
frame->nb_samples = PAF_SOUND_SAMPLES * frames;
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
return ret;
output_samples = (int16_t *)frame->data[0];
// codebook of 256 16-bit samples and 8-bit indices to it
for (j = 0; j < frames; j++) {
for (i = 0; i < 256; i++)
cb[i] = sign_extend(AV_RL16(src + i * 2), 16);
src += 256 * 2;
// always 2 channels
for (i = 0; i < PAF_SOUND_SAMPLES * 2; i++)
*output_samples++ = cb[*src++];
}
*got_frame = 1;
return pkt->size;
}
AVCodec ff_paf_audio_decoder = {
.name = "paf_audio",
.long_name = NULL_IF_CONFIG_SMALL("Amazing Studio Packed Animation File Audio"),
.type = AVMEDIA_TYPE_AUDIO,
.id = AV_CODEC_ID_PAF_AUDIO,
.init = paf_audio_init,
.decode = paf_audio_decode,
.capabilities = CODEC_CAP_DR1,
};