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/common.h"
24 #include "libavutil/intreadwrite.h"
27 #define AES3_HEADER_LEN 4
29 typedef struct S302MDecodeContext {
33 static int s302m_parse_frame_header(AVCodecContext *avctx, const uint8_t *buf,
37 int frame_size, channels, bits;
39 if (buf_size <= AES3_HEADER_LEN) {
40 av_log(avctx, AV_LOG_ERROR, "frame is too short\n");
41 return AVERROR_INVALIDDATA;
54 frame_size = (h >> 16) & 0xffff;
55 channels = ((h >> 14) & 0x0003) * 2 + 2;
56 bits = ((h >> 4) & 0x0003) * 4 + 16;
58 if (AES3_HEADER_LEN + frame_size != buf_size || bits > 24) {
59 av_log(avctx, AV_LOG_ERROR, "frame has invalid header\n");
60 return AVERROR_INVALIDDATA;
63 /* Set output properties */
64 avctx->bits_per_coded_sample = bits;
66 avctx->sample_fmt = AV_SAMPLE_FMT_S32;
68 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
70 avctx->channels = channels;
71 avctx->sample_rate = 48000;
72 avctx->bit_rate = 48000 * avctx->channels * (avctx->bits_per_coded_sample + 4) +
73 32 * (48000 / (buf_size * 8 /
75 (avctx->bits_per_coded_sample + 4))));
80 static int s302m_decode_frame(AVCodecContext *avctx, void *data,
81 int *got_frame_ptr, AVPacket *avpkt)
83 S302MDecodeContext *s = avctx->priv_data;
84 const uint8_t *buf = avpkt->data;
85 int buf_size = avpkt->size;
88 int frame_size = s302m_parse_frame_header(avctx, buf, buf_size);
92 buf_size -= AES3_HEADER_LEN;
93 buf += AES3_HEADER_LEN;
95 /* get output buffer */
96 block_size = (avctx->bits_per_coded_sample + 4) / 4;
97 s->frame.nb_samples = 2 * (buf_size / block_size) / avctx->channels;
98 if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
99 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
103 buf_size = (s->frame.nb_samples * avctx->channels / 2) * block_size;
105 if (avctx->bits_per_coded_sample == 24) {
106 uint32_t *o = (uint32_t *)s->frame.data[0];
107 for (; buf_size > 6; buf_size -= 7) {
108 *o++ = (av_reverse[buf[2]] << 24) |
109 (av_reverse[buf[1]] << 16) |
110 (av_reverse[buf[0]] << 8);
111 *o++ = (av_reverse[buf[6] & 0xf0] << 28) |
112 (av_reverse[buf[5]] << 20) |
113 (av_reverse[buf[4]] << 12) |
114 (av_reverse[buf[3] & 0x0f] << 4);
117 } else if (avctx->bits_per_coded_sample == 20) {
118 uint32_t *o = (uint32_t *)s->frame.data[0];
119 for (; buf_size > 5; buf_size -= 6) {
120 *o++ = (av_reverse[buf[2] & 0xf0] << 28) |
121 (av_reverse[buf[1]] << 20) |
122 (av_reverse[buf[0]] << 12);
123 *o++ = (av_reverse[buf[5] & 0xf0] << 28) |
124 (av_reverse[buf[4]] << 20) |
125 (av_reverse[buf[3]] << 12);
129 uint16_t *o = (uint16_t *)s->frame.data[0];
130 for (; buf_size > 4; buf_size -= 5) {
131 *o++ = (av_reverse[buf[1]] << 8) |
133 *o++ = (av_reverse[buf[4] & 0xf0] << 12) |
134 (av_reverse[buf[3]] << 4) |
135 (av_reverse[buf[2]] >> 4);
141 *(AVFrame *)data = s->frame;
146 static int s302m_decode_init(AVCodecContext *avctx)
148 S302MDecodeContext *s = avctx->priv_data;
150 avcodec_get_frame_defaults(&s->frame);
151 avctx->coded_frame = &s->frame;
157 AVCodec ff_s302m_decoder = {
159 .type = AVMEDIA_TYPE_AUDIO,
160 .id = AV_CODEC_ID_S302M,
161 .priv_data_size = sizeof(S302MDecodeContext),
162 .init = s302m_decode_init,
163 .decode = s302m_decode_frame,
164 .capabilities = CODEC_CAP_DR1,
165 .long_name = NULL_IF_CONFIG_SMALL("SMPTE 302M"),