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"
24 #include "libavutil/log.h"
29 #define AES3_HEADER_LEN 4
31 typedef struct S302MDecodeContext {
35 static int s302m_parse_frame_header(AVCodecContext *avctx, const uint8_t *buf,
39 int frame_size, channels, bits;
41 if (buf_size <= AES3_HEADER_LEN) {
42 av_log(avctx, AV_LOG_ERROR, "frame is too short\n");
43 return AVERROR_INVALIDDATA;
56 frame_size = (h >> 16) & 0xffff;
57 channels = ((h >> 14) & 0x0003) * 2 + 2;
58 bits = ((h >> 4) & 0x0003) * 4 + 16;
60 if (AES3_HEADER_LEN + frame_size != buf_size || bits > 24) {
61 av_log(avctx, AV_LOG_ERROR, "frame has invalid header\n");
62 return AVERROR_INVALIDDATA;
65 /* Set output properties */
66 avctx->bits_per_coded_sample = bits;
68 avctx->sample_fmt = AV_SAMPLE_FMT_S32;
70 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
72 avctx->channels = channels;
73 avctx->sample_rate = 48000;
74 avctx->bit_rate = 48000 * avctx->channels * (avctx->bits_per_coded_sample + 4) +
75 32 * (48000 / (buf_size * 8 /
77 (avctx->bits_per_coded_sample + 4))));
82 static int s302m_decode_frame(AVCodecContext *avctx, void *data,
83 int *got_frame_ptr, AVPacket *avpkt)
85 S302MDecodeContext *s = avctx->priv_data;
86 const uint8_t *buf = avpkt->data;
87 int buf_size = avpkt->size;
90 int frame_size = s302m_parse_frame_header(avctx, buf, buf_size);
94 buf_size -= AES3_HEADER_LEN;
95 buf += AES3_HEADER_LEN;
97 /* get output buffer */
98 block_size = (avctx->bits_per_coded_sample + 4) / 4;
99 s->frame.nb_samples = 2 * (buf_size / block_size) / avctx->channels;
100 if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {
101 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
105 buf_size = (s->frame.nb_samples * avctx->channels / 2) * block_size;
107 if (avctx->bits_per_coded_sample == 24) {
108 uint32_t *o = (uint32_t *)s->frame.data[0];
109 for (; buf_size > 6; buf_size -= 7) {
110 *o++ = (ff_reverse[buf[2]] << 24) |
111 (ff_reverse[buf[1]] << 16) |
112 (ff_reverse[buf[0]] << 8);
113 *o++ = (ff_reverse[buf[6] & 0xf0] << 28) |
114 (ff_reverse[buf[5]] << 20) |
115 (ff_reverse[buf[4]] << 12) |
116 (ff_reverse[buf[3] & 0x0f] << 4);
119 } else if (avctx->bits_per_coded_sample == 20) {
120 uint32_t *o = (uint32_t *)s->frame.data[0];
121 for (; buf_size > 5; buf_size -= 6) {
122 *o++ = (ff_reverse[buf[2] & 0xf0] << 28) |
123 (ff_reverse[buf[1]] << 20) |
124 (ff_reverse[buf[0]] << 12);
125 *o++ = (ff_reverse[buf[5] & 0xf0] << 28) |
126 (ff_reverse[buf[4]] << 20) |
127 (ff_reverse[buf[3]] << 12);
131 uint16_t *o = (uint16_t *)s->frame.data[0];
132 for (; buf_size > 4; buf_size -= 5) {
133 *o++ = (ff_reverse[buf[1]] << 8) |
135 *o++ = (ff_reverse[buf[4] & 0xf0] << 12) |
136 (ff_reverse[buf[3]] << 4) |
137 (ff_reverse[buf[2]] >> 4);
143 *(AVFrame *)data = s->frame;
148 static int s302m_decode_init(AVCodecContext *avctx)
150 S302MDecodeContext *s = avctx->priv_data;
152 avcodec_get_frame_defaults(&s->frame);
153 avctx->coded_frame = &s->frame;
159 AVCodec ff_s302m_decoder = {
161 .type = AVMEDIA_TYPE_AUDIO,
162 .id = AV_CODEC_ID_S302M,
163 .priv_data_size = sizeof(S302MDecodeContext),
164 .init = s302m_decode_init,
165 .decode = s302m_decode_frame,
166 .capabilities = CODEC_CAP_DR1,
167 .long_name = NULL_IF_CONFIG_SMALL("SMPTE 302M"),