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 Libav.
8 * Libav 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 * Libav 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 Libav; 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 static int s302m_parse_frame_header(AVCodecContext *avctx, const uint8_t *buf,
32 int frame_size, channels, bits;
34 if (buf_size <= AES3_HEADER_LEN) {
35 av_log(avctx, AV_LOG_ERROR, "frame is too short\n");
36 return AVERROR_INVALIDDATA;
49 frame_size = (h >> 16) & 0xffff;
50 channels = ((h >> 14) & 0x0003) * 2 + 2;
51 bits = ((h >> 4) & 0x0003) * 4 + 16;
53 if (AES3_HEADER_LEN + frame_size != buf_size || bits > 24) {
54 av_log(avctx, AV_LOG_ERROR, "frame has invalid header\n");
55 return AVERROR_INVALIDDATA;
58 /* Set output properties */
59 avctx->bits_per_coded_sample = bits;
61 avctx->sample_fmt = AV_SAMPLE_FMT_S32;
63 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
65 avctx->channels = channels;
66 avctx->sample_rate = 48000;
67 avctx->bit_rate = 48000 * avctx->channels * (avctx->bits_per_coded_sample + 4) +
68 32 * (48000 / (buf_size * 8 /
70 (avctx->bits_per_coded_sample + 4))));
75 static int s302m_decode_frame(AVCodecContext *avctx, void *data,
76 int *data_size, AVPacket *avpkt)
78 const uint8_t *buf = avpkt->data;
79 int buf_size = avpkt->size;
81 int frame_size = s302m_parse_frame_header(avctx, buf, buf_size);
85 buf_size -= AES3_HEADER_LEN;
86 buf += AES3_HEADER_LEN;
88 if (*data_size < 4 * buf_size * 8 / (avctx->bits_per_coded_sample + 4))
91 if (avctx->bits_per_coded_sample == 24) {
93 for (; buf_size > 6; buf_size -= 7) {
94 *o++ = (av_reverse[buf[2]] << 24) |
95 (av_reverse[buf[1]] << 16) |
96 (av_reverse[buf[0]] << 8);
97 *o++ = (av_reverse[buf[6] & 0xf0] << 28) |
98 (av_reverse[buf[5]] << 20) |
99 (av_reverse[buf[4]] << 12) |
100 (av_reverse[buf[3] & 0x0f] << 4);
103 *data_size = (uint8_t*) o - (uint8_t*) data;
104 } else if (avctx->bits_per_coded_sample == 20) {
106 for (; buf_size > 5; buf_size -= 6) {
107 *o++ = (av_reverse[buf[2] & 0xf0] << 28) |
108 (av_reverse[buf[1]] << 20) |
109 (av_reverse[buf[0]] << 12);
110 *o++ = (av_reverse[buf[5] & 0xf0] << 28) |
111 (av_reverse[buf[4]] << 20) |
112 (av_reverse[buf[3]] << 12);
115 *data_size = (uint8_t*) o - (uint8_t*) data;
118 for (; buf_size > 4; buf_size -= 5) {
119 *o++ = (av_reverse[buf[1]] << 8) |
121 *o++ = (av_reverse[buf[4] & 0xf0] << 12) |
122 (av_reverse[buf[3]] << 4) |
123 (av_reverse[buf[2]] >> 4);
126 *data_size = (uint8_t*) o - (uint8_t*) data;
129 return buf - avpkt->data;
133 AVCodec ff_s302m_decoder = {
135 .type = AVMEDIA_TYPE_AUDIO,
136 .id = CODEC_ID_S302M,
138 .decode = s302m_decode_frame,
139 .long_name = NULL_IF_CONFIG_SMALL("SMPTE 302M"),