1/*
2 * Copyright (c) 2012 Laurent Aimar
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#include "libavutil/channel_layout.h"
22#include "libavutil/intreadwrite.h"
23#include "avcodec.h"
24#include "codec_internal.h"
25#include "internal.h"
26#include "dvaudio.h"
27
28typedef struct DVAudioContext {
29    int block_size;
30    int is_12bit;
31    int is_pal;
32    int16_t shuffle[2000];
33} DVAudioContext;
34
35static av_cold int decode_init(AVCodecContext *avctx)
36{
37    DVAudioContext *s = avctx->priv_data;
38    int i;
39
40    if (avctx->codec_tag == 0x0215) {
41        s->block_size = 7200;
42    } else if (avctx->codec_tag == 0x0216) {
43        s->block_size = 8640;
44    } else if (avctx->block_align == 7200 ||
45               avctx->block_align == 8640) {
46        s->block_size = avctx->block_align;
47    } else {
48        return AVERROR(EINVAL);
49    }
50
51    s->is_pal = s->block_size == 8640;
52    s->is_12bit = avctx->bits_per_coded_sample == 12;
53    avctx->sample_fmt = AV_SAMPLE_FMT_S16;
54    av_channel_layout_uninit(&avctx->ch_layout);
55    avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO;
56
57    for (i = 0; i < FF_ARRAY_ELEMS(s->shuffle); i++) {
58        const unsigned a = s->is_pal ? 18 : 15;
59        const unsigned b = 3 * a;
60
61        s->shuffle[i] = 80 * ((21 * (i % 3) + 9 * (i / 3) + ((i / a) % 3)) % b) +
62                         (2 + s->is_12bit) * (i / b) + 8;
63    }
64
65    return 0;
66}
67
68static inline uint16_t dv_audio_12to16(uint16_t sample)
69{
70    uint16_t shift, result;
71
72    sample = (sample < 0x800) ? sample : sample | 0xf000;
73    shift  = (sample & 0xf00) >> 8;
74
75    if (shift < 0x2 || shift > 0xd) {
76        result = sample;
77    } else if (shift < 0x8) {
78        shift--;
79        result = (sample - (256 * shift)) << shift;
80    } else {
81        shift  = 0xe - shift;
82        result = ((sample + ((256 * shift) + 1)) << shift) - 1;
83    }
84
85    return result;
86}
87
88static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
89                        int *got_frame_ptr, AVPacket *pkt)
90{
91    DVAudioContext *s = avctx->priv_data;
92    const uint8_t *src = pkt->data;
93    int16_t *dst;
94    int ret, i;
95
96    if (pkt->size < s->block_size)
97        return AVERROR_INVALIDDATA;
98
99    frame->nb_samples = dv_get_audio_sample_count(pkt->data + 244, s->is_pal);
100    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
101        return ret;
102    dst = (int16_t *)frame->data[0];
103
104    for (i = 0; i < frame->nb_samples; i++) {
105       const uint8_t *v = &src[s->shuffle[i]];
106
107       if (s->is_12bit) {
108           *dst++ = dv_audio_12to16((v[0] << 4) | ((v[2] >> 4) & 0x0f));
109           *dst++ = dv_audio_12to16((v[1] << 4) | ((v[2] >> 0) & 0x0f));
110       } else {
111           *dst++ = AV_RB16(&v[0]);
112           *dst++ = AV_RB16(&v[s->is_pal ? 4320 : 3600]);
113       }
114    }
115
116    *got_frame_ptr = 1;
117
118    return s->block_size;
119}
120
121const FFCodec ff_dvaudio_decoder = {
122    .p.name         = "dvaudio",
123    .p.long_name    = NULL_IF_CONFIG_SMALL("Ulead DV Audio"),
124    .p.type         = AVMEDIA_TYPE_AUDIO,
125    .p.id           = AV_CODEC_ID_DVAUDIO,
126    .init           = decode_init,
127    FF_CODEC_DECODE_CB(decode_frame),
128    .p.capabilities = AV_CODEC_CAP_DR1,
129    .priv_data_size = sizeof(DVAudioContext),
130    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
131};
132