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"
24 #include "libavutil/log.h"
28 #define AES3_HEADER_LEN 4
30 typedef struct S302MDecodeContext {
34 static int s302m_parse_frame_header(AVCodecContext *avctx, const uint8_t *buf,
38 int frame_size, channels, bits;
40 if (buf_size <= AES3_HEADER_LEN) {
41 av_log(avctx, AV_LOG_ERROR, "frame is too short\n");
42 return AVERROR_INVALIDDATA;
55 frame_size = (h >> 16) & 0xffff;
56 channels = ((h >> 14) & 0x0003) * 2 + 2;
57 bits = ((h >> 4) & 0x0003) * 4 + 16;
59 if (AES3_HEADER_LEN + frame_size != buf_size || bits > 24) {
60 av_log(avctx, AV_LOG_ERROR, "frame has invalid header\n");
61 return AVERROR_INVALIDDATA;
64 /* Set output properties */
65 avctx->bits_per_coded_sample = bits;
67 avctx->sample_fmt = AV_SAMPLE_FMT_S32;
69 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
71 avctx->channels = channels;
74 avctx->channel_layout = AV_CH_LAYOUT_STEREO;
77 avctx->channel_layout = AV_CH_LAYOUT_QUAD;
80 avctx->channel_layout = AV_CH_LAYOUT_5POINT1_BACK;
83 avctx->channel_layout = AV_CH_LAYOUT_5POINT1_BACK | AV_CH_LAYOUT_STEREO_DOWNMIX;
85 avctx->sample_rate = 48000;
86 avctx->bit_rate = 48000 * avctx->channels * (avctx->bits_per_coded_sample + 4) +
87 32 * (48000 / (buf_size * 8 /
89 (avctx->bits_per_coded_sample + 4))));
94 static int s302m_decode_frame(AVCodecContext *avctx, void *data,
95 int *got_frame_ptr, AVPacket *avpkt)
97 S302MDecodeContext *s = avctx->priv_data;
98 const uint8_t *buf = avpkt->data;
99 int buf_size = avpkt->size;
102 int frame_size = s302m_parse_frame_header(avctx, buf, buf_size);
106 buf_size -= AES3_HEADER_LEN;
107 buf += AES3_HEADER_LEN;
109 /* get output buffer */
110 block_size = (avctx->bits_per_coded_sample + 4) / 4;
111 s->frame.nb_samples = 2 * (buf_size / block_size) / avctx->channels;
112 if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
113 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
117 buf_size = (s->frame.nb_samples * avctx->channels / 2) * block_size;
119 if (avctx->bits_per_coded_sample == 24) {
120 uint32_t *o = (uint32_t *)s->frame.data[0];
121 for (; buf_size > 6; buf_size -= 7) {
122 *o++ = (ff_reverse[buf[2]] << 24) |
123 (ff_reverse[buf[1]] << 16) |
124 (ff_reverse[buf[0]] << 8);
125 *o++ = (ff_reverse[buf[6] & 0xf0] << 28) |
126 (ff_reverse[buf[5]] << 20) |
127 (ff_reverse[buf[4]] << 12) |
128 (ff_reverse[buf[3] & 0x0f] << 4);
131 } else if (avctx->bits_per_coded_sample == 20) {
132 uint32_t *o = (uint32_t *)s->frame.data[0];
133 for (; buf_size > 5; buf_size -= 6) {
134 *o++ = (ff_reverse[buf[2] & 0xf0] << 28) |
135 (ff_reverse[buf[1]] << 20) |
136 (ff_reverse[buf[0]] << 12);
137 *o++ = (ff_reverse[buf[5] & 0xf0] << 28) |
138 (ff_reverse[buf[4]] << 20) |
139 (ff_reverse[buf[3]] << 12);
143 uint16_t *o = (uint16_t *)s->frame.data[0];
144 for (; buf_size > 4; buf_size -= 5) {
145 *o++ = (ff_reverse[buf[1]] << 8) |
147 *o++ = (ff_reverse[buf[4] & 0xf0] << 12) |
148 (ff_reverse[buf[3]] << 4) |
149 (ff_reverse[buf[2]] >> 4);
155 *(AVFrame *)data = s->frame;
160 static int s302m_decode_init(AVCodecContext *avctx)
162 S302MDecodeContext *s = avctx->priv_data;
164 avcodec_get_frame_defaults(&s->frame);
165 avctx->coded_frame = &s->frame;
171 AVCodec ff_s302m_decoder = {
173 .type = AVMEDIA_TYPE_AUDIO,
174 .id = AV_CODEC_ID_S302M,
175 .priv_data_size = sizeof(S302MDecodeContext),
176 .init = s302m_decode_init,
177 .decode = s302m_decode_frame,
178 .capabilities = CODEC_CAP_DR1,
179 .long_name = NULL_IF_CONFIG_SMALL("SMPTE 302M"),