1/*
2 * Packed Animation File audio decoder
3 * Copyright (c) 2012 Paul B Mahol
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22#include "libavutil/intreadwrite.h"
23
24#include "avcodec.h"
25#include "internal.h"
26#include "mathops.h"
27
28#define PAF_SOUND_SAMPLES     2205
29#define PAF_SOUND_FRAME_SIZE  ((256 + PAF_SOUND_SAMPLES) * 2)
30
31static av_cold int paf_audio_init(AVCodecContext *avctx)
32{
33    if (avctx->channels != 2) {
34        av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n");
35        return AVERROR_INVALIDDATA;
36    }
37
38    avctx->channel_layout = AV_CH_LAYOUT_STEREO;
39    avctx->sample_fmt     = AV_SAMPLE_FMT_S16;
40
41    return 0;
42}
43
44static int paf_audio_decode(AVCodecContext *avctx, void *data,
45                            int *got_frame, AVPacket *pkt)
46{
47    AVFrame *frame = data;
48    int16_t *output_samples;
49    const uint8_t *src = pkt->data;
50    int frames, ret, i, j;
51    int16_t cb[256];
52
53    frames = pkt->size / PAF_SOUND_FRAME_SIZE;
54    if (frames < 1)
55        return AVERROR_INVALIDDATA;
56
57    frame->nb_samples = PAF_SOUND_SAMPLES * frames;
58    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
59        return ret;
60
61    output_samples = (int16_t *)frame->data[0];
62    // codebook of 256 16-bit samples and 8-bit indices to it
63    for (j = 0; j < frames; j++) {
64        for (i = 0; i < 256; i++)
65            cb[i] = sign_extend(AV_RL16(src + i * 2), 16);
66        src += 256 * 2;
67        // always 2 channels
68        for (i = 0; i < PAF_SOUND_SAMPLES * 2; i++)
69            *output_samples++ = cb[*src++];
70    }
71    *got_frame = 1;
72
73    return pkt->size;
74}
75
76AVCodec ff_paf_audio_decoder = {
77    .name         = "paf_audio",
78    .long_name    = NULL_IF_CONFIG_SMALL("Amazing Studio Packed Animation File Audio"),
79    .type         = AVMEDIA_TYPE_AUDIO,
80    .id           = AV_CODEC_ID_PAF_AUDIO,
81    .init         = paf_audio_init,
82    .decode       = paf_audio_decode,
83    .capabilities = CODEC_CAP_DR1,
84};
85