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/channel_layout.h" 24#include "libavutil/intreadwrite.h" 25#include "libavutil/opt.h" 26#include "libavutil/log.h" 27#include "libavutil/reverse.h" 28#include "avcodec.h" 29#include "codec_internal.h" 30#include "internal.h" 31#include "mathops.h" 32 33#define AES3_HEADER_LEN 4 34 35typedef struct S302Context { 36 AVClass *class; 37 int non_pcm_mode; 38} S302Context; 39 40static int s302m_parse_frame_header(AVCodecContext *avctx, const uint8_t *buf, 41 int buf_size) 42{ 43 uint32_t h; 44 int frame_size, channels, bits; 45 46 if (buf_size <= AES3_HEADER_LEN) { 47 av_log(avctx, AV_LOG_ERROR, "frame is too short\n"); 48 return AVERROR_INVALIDDATA; 49 } 50 51 /* 52 * AES3 header : 53 * size: 16 54 * number channels 2 55 * channel_id 8 56 * bits per samples 2 57 * alignments 4 58 */ 59 60 h = AV_RB32(buf); 61 frame_size = (h >> 16) & 0xffff; 62 channels = ((h >> 14) & 0x0003) * 2 + 2; 63 bits = ((h >> 4) & 0x0003) * 4 + 16; 64 65 if (AES3_HEADER_LEN + frame_size != buf_size || bits > 24) { 66 av_log(avctx, AV_LOG_ERROR, "frame has invalid header\n"); 67 return AVERROR_INVALIDDATA; 68 } 69 70 /* Set output properties */ 71 avctx->bits_per_raw_sample = bits; 72 if (bits > 16) 73 avctx->sample_fmt = AV_SAMPLE_FMT_S32; 74 else 75 avctx->sample_fmt = AV_SAMPLE_FMT_S16; 76 77 av_channel_layout_uninit(&avctx->ch_layout); 78 switch(channels) { 79 case 2: 80 avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO; 81 break; 82 case 4: 83 avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_QUAD; 84 break; 85 case 6: 86 avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_5POINT1_BACK; 87 break; 88 case 8: 89 av_channel_layout_from_mask(&avctx->ch_layout, 90 AV_CH_LAYOUT_5POINT1_BACK | AV_CH_LAYOUT_STEREO_DOWNMIX); 91 break; 92 default: 93 avctx->ch_layout.order = AV_CHANNEL_ORDER_UNSPEC; 94 avctx->ch_layout.nb_channels = channels; 95 break; 96 } 97 98 return frame_size; 99} 100 101static int s302m_decode_frame(AVCodecContext *avctx, AVFrame *frame, 102 int *got_frame_ptr, AVPacket *avpkt) 103{ 104 S302Context *s = avctx->priv_data; 105 const uint8_t *buf = avpkt->data; 106 int buf_size = avpkt->size; 107 int block_size, ret, channels; 108 int i; 109 int non_pcm_data_type = -1; 110 111 int frame_size = s302m_parse_frame_header(avctx, buf, buf_size); 112 if (frame_size < 0) 113 return frame_size; 114 115 buf_size -= AES3_HEADER_LEN; 116 buf += AES3_HEADER_LEN; 117 118 /* get output buffer */ 119 block_size = (avctx->bits_per_raw_sample + 4) / 4; 120 channels = avctx->ch_layout.nb_channels; 121 frame->nb_samples = 2 * (buf_size / block_size) / channels; 122 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) 123 return ret; 124 125 avctx->bit_rate = 48000 * channels * (avctx->bits_per_raw_sample + 4) + 126 32 * 48000 / frame->nb_samples; 127 buf_size = (frame->nb_samples * channels / 2) * block_size; 128 129 if (avctx->bits_per_raw_sample == 24) { 130 uint32_t *o = (uint32_t *)frame->data[0]; 131 for (; buf_size > 6; buf_size -= 7) { 132 *o++ = ((unsigned)ff_reverse[buf[2]] << 24) | 133 (ff_reverse[buf[1]] << 16) | 134 (ff_reverse[buf[0]] << 8); 135 *o++ = ((unsigned)ff_reverse[buf[6] & 0xf0] << 28) | 136 (ff_reverse[buf[5]] << 20) | 137 (ff_reverse[buf[4]] << 12) | 138 (ff_reverse[buf[3] & 0x0f] << 4); 139 buf += 7; 140 } 141 o = (uint32_t *)frame->data[0]; 142 if (channels == 2) 143 for (i=0; i<frame->nb_samples * 2 - 6; i+=2) { 144 if (o[i] || o[i+1] || o[i+2] || o[i+3]) 145 break; 146 if (o[i+4] == 0x96F87200U && o[i+5] == 0xA54E1F00) { 147 non_pcm_data_type = (o[i+6] >> 16) & 0x1F; 148 break; 149 } 150 } 151 } else if (avctx->bits_per_raw_sample == 20) { 152 uint32_t *o = (uint32_t *)frame->data[0]; 153 for (; buf_size > 5; buf_size -= 6) { 154 *o++ = ((unsigned)ff_reverse[buf[2] & 0xf0] << 28) | 155 (ff_reverse[buf[1]] << 20) | 156 (ff_reverse[buf[0]] << 12); 157 *o++ = ((unsigned)ff_reverse[buf[5] & 0xf0] << 28) | 158 (ff_reverse[buf[4]] << 20) | 159 (ff_reverse[buf[3]] << 12); 160 buf += 6; 161 } 162 o = (uint32_t *)frame->data[0]; 163 if (channels == 2) 164 for (i=0; i<frame->nb_samples * 2 - 6; i+=2) { 165 if (o[i] || o[i+1] || o[i+2] || o[i+3]) 166 break; 167 if (o[i+4] == 0x6F872000U && o[i+5] == 0x54E1F000) { 168 non_pcm_data_type = (o[i+6] >> 16) & 0x1F; 169 break; 170 } 171 } 172 } else { 173 uint16_t *o = (uint16_t *)frame->data[0]; 174 for (; buf_size > 4; buf_size -= 5) { 175 *o++ = (ff_reverse[buf[1]] << 8) | 176 ff_reverse[buf[0]]; 177 *o++ = (ff_reverse[buf[4] & 0xf0] << 12) | 178 (ff_reverse[buf[3]] << 4) | 179 (ff_reverse[buf[2]] >> 4); 180 buf += 5; 181 } 182 o = (uint16_t *)frame->data[0]; 183 if (channels == 2) 184 for (i=0; i<frame->nb_samples * 2 - 6; i+=2) { 185 if (o[i] || o[i+1] || o[i+2] || o[i+3]) 186 break; 187 if (o[i+4] == 0xF872U && o[i+5] == 0x4E1F) { 188 non_pcm_data_type = (o[i+6] & 0x1F); 189 break; 190 } 191 } 192 } 193 194 if (non_pcm_data_type != -1) { 195 if (s->non_pcm_mode == 3) { 196 av_log(avctx, AV_LOG_ERROR, 197 "S302 non PCM mode with data type %d not supported\n", 198 non_pcm_data_type); 199 return AVERROR_PATCHWELCOME; 200 } 201 if (s->non_pcm_mode & 1) { 202 return avpkt->size; 203 } 204 } 205 206 avctx->sample_rate = 48000; 207 208 *got_frame_ptr = 1; 209 210 return avpkt->size; 211} 212 213#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_DECODING_PARAM 214static const AVOption s302m_options[] = { 215 {"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"}, 216 {"copy" , "Pass NON-PCM through unchanged" , 0, AV_OPT_TYPE_CONST, {.i64 = 0}, 0, 3, FLAGS, "non_pcm_mode"}, 217 {"drop" , "Drop NON-PCM" , 0, AV_OPT_TYPE_CONST, {.i64 = 1}, 0, 3, FLAGS, "non_pcm_mode"}, 218 {"decode_copy" , "Decode if possible else passthrough", 0, AV_OPT_TYPE_CONST, {.i64 = 2}, 0, 3, FLAGS, "non_pcm_mode"}, 219 {"decode_drop" , "Decode if possible else drop" , 0, AV_OPT_TYPE_CONST, {.i64 = 3}, 0, 3, FLAGS, "non_pcm_mode"}, 220 {NULL} 221}; 222 223static const AVClass s302m_class = { 224 .class_name = "SMPTE 302M Decoder", 225 .item_name = av_default_item_name, 226 .option = s302m_options, 227 .version = LIBAVUTIL_VERSION_INT, 228}; 229 230const FFCodec ff_s302m_decoder = { 231 .p.name = "s302m", 232 .p.long_name = NULL_IF_CONFIG_SMALL("SMPTE 302M"), 233 .p.type = AVMEDIA_TYPE_AUDIO, 234 .p.id = AV_CODEC_ID_S302M, 235 .p.priv_class = &s302m_class, 236 .priv_data_size = sizeof(S302Context), 237 FF_CODEC_DECODE_CB(s302m_decode_frame), 238 .p.capabilities = AV_CODEC_CAP_CHANNEL_CONF | 239 AV_CODEC_CAP_DR1, 240}; 241