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path: root/libavcodec/s302m.c (plain)
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1/*
2 * SMPTE 302M decoder
3 * Copyright (c) 2008 Laurent Aimar <fenrir@videolan.org>
4 * Copyright (c) 2009 Baptiste Coudurier <baptiste.coudurier@gmail.com>
5 *
6 * This file is part of FFmpeg.
7 *
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.
12 *
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.
17 *
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
21 */
22
23#include "libavutil/intreadwrite.h"
24#include "libavutil/opt.h"
25#include "libavutil/log.h"
26#include "avcodec.h"
27#include "internal.h"
28#include "mathops.h"
29
30#define AES3_HEADER_LEN 4
31
32typedef struct S302Context {
33 AVClass *class;
34 int non_pcm_mode;
35} S302Context;
36
37static int s302m_parse_frame_header(AVCodecContext *avctx, const uint8_t *buf,
38 int buf_size)
39{
40 uint32_t h;
41 int frame_size, channels, bits;
42
43 if (buf_size <= AES3_HEADER_LEN) {
44 av_log(avctx, AV_LOG_ERROR, "frame is too short\n");
45 return AVERROR_INVALIDDATA;
46 }
47
48 /*
49 * AES3 header :
50 * size: 16
51 * number channels 2
52 * channel_id 8
53 * bits per samples 2
54 * alignments 4
55 */
56
57 h = AV_RB32(buf);
58 frame_size = (h >> 16) & 0xffff;
59 channels = ((h >> 14) & 0x0003) * 2 + 2;
60 bits = ((h >> 4) & 0x0003) * 4 + 16;
61
62 if (AES3_HEADER_LEN + frame_size != buf_size || bits > 24) {
63 av_log(avctx, AV_LOG_ERROR, "frame has invalid header\n");
64 return AVERROR_INVALIDDATA;
65 }
66
67 /* Set output properties */
68 avctx->bits_per_raw_sample = bits;
69 if (bits > 16)
70 avctx->sample_fmt = AV_SAMPLE_FMT_S32;
71 else
72 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
73
74 avctx->channels = channels;
75 switch(channels) {
76 case 2:
77 avctx->channel_layout = AV_CH_LAYOUT_STEREO;
78 break;
79 case 4:
80 avctx->channel_layout = AV_CH_LAYOUT_QUAD;
81 break;
82 case 6:
83 avctx->channel_layout = AV_CH_LAYOUT_5POINT1_BACK;
84 break;
85 case 8:
86 avctx->channel_layout = AV_CH_LAYOUT_5POINT1_BACK | AV_CH_LAYOUT_STEREO_DOWNMIX;
87 }
88
89 return frame_size;
90}
91
92static int s302m_decode_frame(AVCodecContext *avctx, void *data,
93 int *got_frame_ptr, AVPacket *avpkt)
94{
95 S302Context *s = avctx->priv_data;
96 AVFrame *frame = data;
97 const uint8_t *buf = avpkt->data;
98 int buf_size = avpkt->size;
99 int block_size, ret;
100 int i;
101 int non_pcm_data_type = -1;
102
103 int frame_size = s302m_parse_frame_header(avctx, buf, buf_size);
104 if (frame_size < 0)
105 return frame_size;
106
107 buf_size -= AES3_HEADER_LEN;
108 buf += AES3_HEADER_LEN;
109
110 /* get output buffer */
111 block_size = (avctx->bits_per_raw_sample + 4) / 4;
112 frame->nb_samples = 2 * (buf_size / block_size) / avctx->channels;
113 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
114 return ret;
115
116 avctx->bit_rate = 48000 * avctx->channels * (avctx->bits_per_raw_sample + 4) +
117 32 * 48000 / frame->nb_samples;
118 buf_size = (frame->nb_samples * avctx->channels / 2) * block_size;
119
120 if (avctx->bits_per_raw_sample == 24) {
121 uint32_t *o = (uint32_t *)frame->data[0];
122 for (; buf_size > 6; buf_size -= 7) {
123 *o++ = (ff_reverse[buf[2]] << 24) |
124 (ff_reverse[buf[1]] << 16) |
125 (ff_reverse[buf[0]] << 8);
126 *o++ = (ff_reverse[buf[6] & 0xf0] << 28) |
127 (ff_reverse[buf[5]] << 20) |
128 (ff_reverse[buf[4]] << 12) |
129 (ff_reverse[buf[3] & 0x0f] << 4);
130 buf += 7;
131 }
132 o = (uint32_t *)frame->data[0];
133 if (avctx->channels == 2)
134 for (i=0; i<frame->nb_samples * 2 - 6; i+=2) {
135 if (o[i] || o[i+1] || o[i+2] || o[i+3])
136 break;
137 if (o[i+4] == 0x96F87200U && o[i+5] == 0xA54E1F00) {
138 non_pcm_data_type = (o[i+6] >> 16) & 0x1F;
139 break;
140 }
141 }
142 } else if (avctx->bits_per_raw_sample == 20) {
143 uint32_t *o = (uint32_t *)frame->data[0];
144 for (; buf_size > 5; buf_size -= 6) {
145 *o++ = (ff_reverse[buf[2] & 0xf0] << 28) |
146 (ff_reverse[buf[1]] << 20) |
147 (ff_reverse[buf[0]] << 12);
148 *o++ = (ff_reverse[buf[5] & 0xf0] << 28) |
149 (ff_reverse[buf[4]] << 20) |
150 (ff_reverse[buf[3]] << 12);
151 buf += 6;
152 }
153 o = (uint32_t *)frame->data[0];
154 if (avctx->channels == 2)
155 for (i=0; i<frame->nb_samples * 2 - 6; i+=2) {
156 if (o[i] || o[i+1] || o[i+2] || o[i+3])
157 break;
158 if (o[i+4] == 0x6F872000U && o[i+5] == 0x54E1F000) {
159 non_pcm_data_type = (o[i+6] >> 16) & 0x1F;
160 break;
161 }
162 }
163 } else {
164 uint16_t *o = (uint16_t *)frame->data[0];
165 for (; buf_size > 4; buf_size -= 5) {
166 *o++ = (ff_reverse[buf[1]] << 8) |
167 ff_reverse[buf[0]];
168 *o++ = (ff_reverse[buf[4] & 0xf0] << 12) |
169 (ff_reverse[buf[3]] << 4) |
170 (ff_reverse[buf[2]] >> 4);
171 buf += 5;
172 }
173 o = (uint16_t *)frame->data[0];
174 if (avctx->channels == 2)
175 for (i=0; i<frame->nb_samples * 2 - 6; i+=2) {
176 if (o[i] || o[i+1] || o[i+2] || o[i+3])
177 break;
178 if (o[i+4] == 0xF872U && o[i+5] == 0x4E1F) {
179 non_pcm_data_type = (o[i+6] & 0x1F);
180 break;
181 }
182 }
183 }
184
185 if (non_pcm_data_type != -1) {
186 if (s->non_pcm_mode == 3) {
187 av_log(avctx, AV_LOG_ERROR,
188 "S302 non PCM mode with data type %d not supported\n",
189 non_pcm_data_type);
190 return AVERROR_PATCHWELCOME;
191 }
192 if (s->non_pcm_mode & 1) {
193 return avpkt->size;
194 }
195 }
196
197 avctx->sample_rate = 48000;
198
199 *got_frame_ptr = 1;
200
201 return avpkt->size;
202}
203
204#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_DECODING_PARAM
205static const AVOption s302m_options[] = {
206 {"non_pcm_mode", "Chooses what to do with NON-PCM", offsetof(S302Context, non_pcm_mode), AV_OPT_TYPE_INT, {.i64 = 3}, 0, 3, FLAGS, "non_pcm_mode"},
207 {"copy" , "Pass NON-PCM through unchanged" , 0, AV_OPT_TYPE_CONST, {.i64 = 0}, 0, 3, FLAGS, "non_pcm_mode"},
208 {"drop" , "Drop NON-PCM" , 0, AV_OPT_TYPE_CONST, {.i64 = 1}, 0, 3, FLAGS, "non_pcm_mode"},
209 {"decode_copy" , "Decode if possible else passthrough", 0, AV_OPT_TYPE_CONST, {.i64 = 2}, 0, 3, FLAGS, "non_pcm_mode"},
210 {"decode_drop" , "Decode if possible else drop" , 0, AV_OPT_TYPE_CONST, {.i64 = 3}, 0, 3, FLAGS, "non_pcm_mode"},
211 {NULL}
212};
213
214static const AVClass s302m_class = {
215 "SMPTE 302M Decoder",
216 av_default_item_name,
217 s302m_options,
218 LIBAVUTIL_VERSION_INT,
219};
220
221AVCodec ff_s302m_decoder = {
222 .name = "s302m",
223 .long_name = NULL_IF_CONFIG_SMALL("SMPTE 302M"),
224 .type = AVMEDIA_TYPE_AUDIO,
225 .id = AV_CODEC_ID_S302M,
226 .priv_data_size = sizeof(S302Context),
227 .decode = s302m_decode_frame,
228 .capabilities = AV_CODEC_CAP_DR1,
229 .priv_class = &s302m_class,
230};
231
generated by cgit at 2024-05-17 05:45:23 (GMT)