/* * SMPTE 302M decoder * Copyright (c) 2008 Laurent Aimar * Copyright (c) 2009 Baptiste Coudurier * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "libavutil/channel_layout.h" #include "libavutil/intreadwrite.h" #include "libavutil/opt.h" #include "libavutil/log.h" #include "libavutil/reverse.h" #include "avcodec.h" #include "codec_internal.h" #include "decode.h" #define AES3_HEADER_LEN 4 typedef struct S302Context { AVClass *class; int non_pcm_mode; } S302Context; static int s302m_parse_frame_header(AVCodecContext *avctx, const uint8_t *buf, int buf_size) { uint32_t h; int frame_size, channels, bits; if (buf_size <= AES3_HEADER_LEN) { av_log(avctx, AV_LOG_ERROR, "frame is too short\n"); return AVERROR_INVALIDDATA; } /* * AES3 header : * size: 16 * number channels 2 * channel_id 8 * bits per samples 2 * alignments 4 */ h = AV_RB32(buf); frame_size = (h >> 16) & 0xffff; channels = ((h >> 14) & 0x0003) * 2 + 2; bits = ((h >> 4) & 0x0003) * 4 + 16; if (AES3_HEADER_LEN + frame_size != buf_size || bits > 24) { av_log(avctx, AV_LOG_ERROR, "frame has invalid header\n"); return AVERROR_INVALIDDATA; } /* Set output properties */ avctx->bits_per_raw_sample = bits; if (bits > 16) avctx->sample_fmt = AV_SAMPLE_FMT_S32; else avctx->sample_fmt = AV_SAMPLE_FMT_S16; av_channel_layout_uninit(&avctx->ch_layout); switch(channels) { case 2: avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO; break; case 4: avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_QUAD; break; case 6: avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_5POINT1_BACK; break; case 8: av_channel_layout_from_mask(&avctx->ch_layout, AV_CH_LAYOUT_5POINT1_BACK | AV_CH_LAYOUT_STEREO_DOWNMIX); break; default: avctx->ch_layout.order = AV_CHANNEL_ORDER_UNSPEC; avctx->ch_layout.nb_channels = channels; break; } return frame_size; } static int s302m_decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame_ptr, AVPacket *avpkt) { S302Context *s = avctx->priv_data; const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; int block_size, ret, channels; int i; int non_pcm_data_type = -1; int frame_size = s302m_parse_frame_header(avctx, buf, buf_size); if (frame_size < 0) return frame_size; buf_size -= AES3_HEADER_LEN; buf += AES3_HEADER_LEN; /* get output buffer */ block_size = (avctx->bits_per_raw_sample + 4) / 4; channels = avctx->ch_layout.nb_channels; frame->nb_samples = 2 * (buf_size / block_size) / channels; if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) return ret; avctx->bit_rate = 48000 * channels * (avctx->bits_per_raw_sample + 4) + 32 * 48000 / frame->nb_samples; buf_size = (frame->nb_samples * channels / 2) * block_size; if (avctx->bits_per_raw_sample == 24) { uint32_t *o = (uint32_t *)frame->data[0]; for (; buf_size > 6; buf_size -= 7) { *o++ = ((unsigned)ff_reverse[buf[2]] << 24) | (ff_reverse[buf[1]] << 16) | (ff_reverse[buf[0]] << 8); *o++ = ((unsigned)ff_reverse[buf[6] & 0xf0] << 28) | (ff_reverse[buf[5]] << 20) | (ff_reverse[buf[4]] << 12) | (ff_reverse[buf[3] & 0x0f] << 4); buf += 7; } o = (uint32_t *)frame->data[0]; if (channels == 2) for (i=0; inb_samples * 2 - 6; i+=2) { if (o[i] || o[i+1] || o[i+2] || o[i+3]) break; if (o[i+4] == 0x96F87200U && o[i+5] == 0xA54E1F00) { non_pcm_data_type = (o[i+6] >> 16) & 0x1F; break; } } } else if (avctx->bits_per_raw_sample == 20) { uint32_t *o = (uint32_t *)frame->data[0]; for (; buf_size > 5; buf_size -= 6) { *o++ = ((unsigned)ff_reverse[buf[2] & 0xf0] << 28) | (ff_reverse[buf[1]] << 20) | (ff_reverse[buf[0]] << 12); *o++ = ((unsigned)ff_reverse[buf[5] & 0xf0] << 28) | (ff_reverse[buf[4]] << 20) | (ff_reverse[buf[3]] << 12); buf += 6; } o = (uint32_t *)frame->data[0]; if (channels == 2) for (i=0; inb_samples * 2 - 6; i+=2) { if (o[i] || o[i+1] || o[i+2] || o[i+3]) break; if (o[i+4] == 0x6F872000U && o[i+5] == 0x54E1F000) { non_pcm_data_type = (o[i+6] >> 16) & 0x1F; break; } } } else { uint16_t *o = (uint16_t *)frame->data[0]; for (; buf_size > 4; buf_size -= 5) { *o++ = (ff_reverse[buf[1]] << 8) | ff_reverse[buf[0]]; *o++ = (ff_reverse[buf[4] & 0xf0] << 12) | (ff_reverse[buf[3]] << 4) | (ff_reverse[buf[2]] >> 4); buf += 5; } o = (uint16_t *)frame->data[0]; if (channels == 2) for (i=0; inb_samples * 2 - 6; i+=2) { if (o[i] || o[i+1] || o[i+2] || o[i+3]) break; if (o[i+4] == 0xF872U && o[i+5] == 0x4E1F) { non_pcm_data_type = (o[i+6] & 0x1F); break; } } } if (non_pcm_data_type != -1) { if (s->non_pcm_mode == 3) { av_log(avctx, AV_LOG_ERROR, "S302 non PCM mode with data type %d not supported\n", non_pcm_data_type); return AVERROR_PATCHWELCOME; } if (s->non_pcm_mode & 1) { return avpkt->size; } } avctx->sample_rate = 48000; *got_frame_ptr = 1; return avpkt->size; } #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_DECODING_PARAM static const AVOption s302m_options[] = { {"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"}, {"copy" , "Pass NON-PCM through unchanged" , 0, AV_OPT_TYPE_CONST, {.i64 = 0}, 0, 3, FLAGS, "non_pcm_mode"}, {"drop" , "Drop NON-PCM" , 0, AV_OPT_TYPE_CONST, {.i64 = 1}, 0, 3, FLAGS, "non_pcm_mode"}, {"decode_copy" , "Decode if possible else passthrough", 0, AV_OPT_TYPE_CONST, {.i64 = 2}, 0, 3, FLAGS, "non_pcm_mode"}, {"decode_drop" , "Decode if possible else drop" , 0, AV_OPT_TYPE_CONST, {.i64 = 3}, 0, 3, FLAGS, "non_pcm_mode"}, {NULL} }; static const AVClass s302m_class = { .class_name = "SMPTE 302M Decoder", .item_name = av_default_item_name, .option = s302m_options, .version = LIBAVUTIL_VERSION_INT, }; const FFCodec ff_s302m_decoder = { .p.name = "s302m", CODEC_LONG_NAME("SMPTE 302M"), .p.type = AVMEDIA_TYPE_AUDIO, .p.id = AV_CODEC_ID_S302M, .p.priv_class = &s302m_class, .priv_data_size = sizeof(S302Context), FF_CODEC_DECODE_CB(s302m_decode_frame), .p.capabilities = AV_CODEC_CAP_CHANNEL_CONF | AV_CODEC_CAP_DR1, };