3 * Copyright (c) 2008 Laurent Aimar <fenrir@videolan.org>
4 * Copyright (c) 2009 Baptiste Coudurier <baptiste.coudurier@gmail.com>
6 * This file is part of FFmpeg.
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 #include "libavutil/intreadwrite.h"
26 #define AES3_HEADER_LEN 4
28 typedef struct S302MDecodeContext {
32 static int s302m_parse_frame_header(AVCodecContext *avctx, const uint8_t *buf,
36 int frame_size, channels, bits;
38 if (buf_size <= AES3_HEADER_LEN) {
39 av_log(avctx, AV_LOG_ERROR, "frame is too short\n");
40 return AVERROR_INVALIDDATA;
53 frame_size = (h >> 16) & 0xffff;
54 channels = ((h >> 14) & 0x0003) * 2 + 2;
55 bits = ((h >> 4) & 0x0003) * 4 + 16;
57 if (AES3_HEADER_LEN + frame_size != buf_size || bits > 24) {
58 av_log(avctx, AV_LOG_ERROR, "frame has invalid header\n");
59 return AVERROR_INVALIDDATA;
62 /* Set output properties */
63 avctx->bits_per_coded_sample = bits;
65 avctx->sample_fmt = AV_SAMPLE_FMT_S32;
67 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
69 avctx->channels = channels;
72 avctx->channel_layout = AV_CH_LAYOUT_STEREO;
75 avctx->channel_layout = AV_CH_LAYOUT_QUAD;
78 avctx->channel_layout = AV_CH_LAYOUT_5POINT1_BACK | AV_CH_LAYOUT_STEREO_DOWNMIX;
80 avctx->sample_rate = 48000;
81 avctx->bit_rate = 48000 * avctx->channels * (avctx->bits_per_coded_sample + 4) +
82 32 * (48000 / (buf_size * 8 /
84 (avctx->bits_per_coded_sample + 4))));
89 static int s302m_decode_frame(AVCodecContext *avctx, void *data,
90 int *got_frame_ptr, AVPacket *avpkt)
92 S302MDecodeContext *s = avctx->priv_data;
93 const uint8_t *buf = avpkt->data;
94 int buf_size = avpkt->size;
97 int frame_size = s302m_parse_frame_header(avctx, buf, buf_size);
101 buf_size -= AES3_HEADER_LEN;
102 buf += AES3_HEADER_LEN;
104 /* get output buffer */
105 block_size = (avctx->bits_per_coded_sample + 4) / 4;
106 s->frame.nb_samples = 2 * (buf_size / block_size) / avctx->channels;
107 if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
108 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
112 buf_size = (s->frame.nb_samples * avctx->channels / 2) * block_size;
114 if (avctx->bits_per_coded_sample == 24) {
115 uint32_t *o = (uint32_t *)s->frame.data[0];
116 for (; buf_size > 6; buf_size -= 7) {
117 *o++ = (av_reverse[buf[2]] << 24) |
118 (av_reverse[buf[1]] << 16) |
119 (av_reverse[buf[0]] << 8);
120 *o++ = (av_reverse[buf[6] & 0xf0] << 28) |
121 (av_reverse[buf[5]] << 20) |
122 (av_reverse[buf[4]] << 12) |
123 (av_reverse[buf[3] & 0x0f] << 4);
126 } else if (avctx->bits_per_coded_sample == 20) {
127 uint32_t *o = (uint32_t *)s->frame.data[0];
128 for (; buf_size > 5; buf_size -= 6) {
129 *o++ = (av_reverse[buf[2] & 0xf0] << 28) |
130 (av_reverse[buf[1]] << 20) |
131 (av_reverse[buf[0]] << 12);
132 *o++ = (av_reverse[buf[5] & 0xf0] << 28) |
133 (av_reverse[buf[4]] << 20) |
134 (av_reverse[buf[3]] << 12);
138 uint16_t *o = (uint16_t *)s->frame.data[0];
139 for (; buf_size > 4; buf_size -= 5) {
140 *o++ = (av_reverse[buf[1]] << 8) |
142 *o++ = (av_reverse[buf[4] & 0xf0] << 12) |
143 (av_reverse[buf[3]] << 4) |
144 (av_reverse[buf[2]] >> 4);
150 *(AVFrame *)data = s->frame;
155 static int s302m_decode_init(AVCodecContext *avctx)
157 S302MDecodeContext *s = avctx->priv_data;
159 avcodec_get_frame_defaults(&s->frame);
160 avctx->coded_frame = &s->frame;
166 AVCodec ff_s302m_decoder = {
168 .type = AVMEDIA_TYPE_AUDIO,
169 .id = CODEC_ID_S302M,
170 .priv_data_size = sizeof(S302MDecodeContext),
171 .init = s302m_decode_init,
172 .decode = s302m_decode_frame,
173 .capabilities = CODEC_CAP_DR1,
174 .long_name = NULL_IF_CONFIG_SMALL("SMPTE 302M"),