yading@10: /* yading@10: * SMPTE 302M decoder yading@10: * Copyright (c) 2008 Laurent Aimar yading@10: * Copyright (c) 2009 Baptiste Coudurier yading@10: * yading@10: * This file is part of FFmpeg. yading@10: * yading@10: * FFmpeg is free software; you can redistribute it and/or yading@10: * modify it under the terms of the GNU Lesser General Public yading@10: * License as published by the Free Software Foundation; either yading@10: * version 2.1 of the License, or (at your option) any later version. yading@10: * yading@10: * FFmpeg is distributed in the hope that it will be useful, yading@10: * but WITHOUT ANY WARRANTY; without even the implied warranty of yading@10: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU yading@10: * Lesser General Public License for more details. yading@10: * yading@10: * You should have received a copy of the GNU Lesser General Public yading@10: * License along with FFmpeg; if not, write to the Free Software yading@10: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA yading@10: */ yading@10: yading@10: #include "libavutil/intreadwrite.h" yading@10: #include "libavutil/log.h" yading@10: #include "avcodec.h" yading@10: #include "internal.h" yading@10: #include "mathops.h" yading@10: yading@10: #define AES3_HEADER_LEN 4 yading@10: yading@10: static int s302m_parse_frame_header(AVCodecContext *avctx, const uint8_t *buf, yading@10: int buf_size) yading@10: { yading@10: uint32_t h; yading@10: int frame_size, channels, bits; yading@10: yading@10: if (buf_size <= AES3_HEADER_LEN) { yading@10: av_log(avctx, AV_LOG_ERROR, "frame is too short\n"); yading@10: return AVERROR_INVALIDDATA; yading@10: } yading@10: yading@10: /* yading@10: * AES3 header : yading@10: * size: 16 yading@10: * number channels 2 yading@10: * channel_id 8 yading@10: * bits per samples 2 yading@10: * alignments 4 yading@10: */ yading@10: yading@10: h = AV_RB32(buf); yading@10: frame_size = (h >> 16) & 0xffff; yading@10: channels = ((h >> 14) & 0x0003) * 2 + 2; yading@10: bits = ((h >> 4) & 0x0003) * 4 + 16; yading@10: yading@10: if (AES3_HEADER_LEN + frame_size != buf_size || bits > 24) { yading@10: av_log(avctx, AV_LOG_ERROR, "frame has invalid header\n"); yading@10: return AVERROR_INVALIDDATA; yading@10: } yading@10: yading@10: /* Set output properties */ yading@10: avctx->bits_per_coded_sample = bits; yading@10: if (bits > 16) yading@10: avctx->sample_fmt = AV_SAMPLE_FMT_S32; yading@10: else yading@10: avctx->sample_fmt = AV_SAMPLE_FMT_S16; yading@10: yading@10: avctx->channels = channels; yading@10: switch(channels) { yading@10: case 2: yading@10: avctx->channel_layout = AV_CH_LAYOUT_STEREO; yading@10: break; yading@10: case 4: yading@10: avctx->channel_layout = AV_CH_LAYOUT_QUAD; yading@10: break; yading@10: case 6: yading@10: avctx->channel_layout = AV_CH_LAYOUT_5POINT1_BACK; yading@10: break; yading@10: case 8: yading@10: avctx->channel_layout = AV_CH_LAYOUT_5POINT1_BACK | AV_CH_LAYOUT_STEREO_DOWNMIX; yading@10: } yading@10: avctx->sample_rate = 48000; yading@10: avctx->bit_rate = 48000 * avctx->channels * (avctx->bits_per_coded_sample + 4) + yading@10: 32 * (48000 / (buf_size * 8 / yading@10: (avctx->channels * yading@10: (avctx->bits_per_coded_sample + 4)))); yading@10: yading@10: return frame_size; yading@10: } yading@10: yading@10: static int s302m_decode_frame(AVCodecContext *avctx, void *data, yading@10: int *got_frame_ptr, AVPacket *avpkt) yading@10: { yading@10: AVFrame *frame = data; yading@10: const uint8_t *buf = avpkt->data; yading@10: int buf_size = avpkt->size; yading@10: int block_size, ret; yading@10: yading@10: int frame_size = s302m_parse_frame_header(avctx, buf, buf_size); yading@10: if (frame_size < 0) yading@10: return frame_size; yading@10: yading@10: buf_size -= AES3_HEADER_LEN; yading@10: buf += AES3_HEADER_LEN; yading@10: yading@10: /* get output buffer */ yading@10: block_size = (avctx->bits_per_coded_sample + 4) / 4; yading@10: frame->nb_samples = 2 * (buf_size / block_size) / avctx->channels; yading@10: if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) yading@10: return ret; yading@10: yading@10: buf_size = (frame->nb_samples * avctx->channels / 2) * block_size; yading@10: yading@10: if (avctx->bits_per_coded_sample == 24) { yading@10: uint32_t *o = (uint32_t *)frame->data[0]; yading@10: for (; buf_size > 6; buf_size -= 7) { yading@10: *o++ = (ff_reverse[buf[2]] << 24) | yading@10: (ff_reverse[buf[1]] << 16) | yading@10: (ff_reverse[buf[0]] << 8); yading@10: *o++ = (ff_reverse[buf[6] & 0xf0] << 28) | yading@10: (ff_reverse[buf[5]] << 20) | yading@10: (ff_reverse[buf[4]] << 12) | yading@10: (ff_reverse[buf[3] & 0x0f] << 4); yading@10: buf += 7; yading@10: } yading@10: } else if (avctx->bits_per_coded_sample == 20) { yading@10: uint32_t *o = (uint32_t *)frame->data[0]; yading@10: for (; buf_size > 5; buf_size -= 6) { yading@10: *o++ = (ff_reverse[buf[2] & 0xf0] << 28) | yading@10: (ff_reverse[buf[1]] << 20) | yading@10: (ff_reverse[buf[0]] << 12); yading@10: *o++ = (ff_reverse[buf[5] & 0xf0] << 28) | yading@10: (ff_reverse[buf[4]] << 20) | yading@10: (ff_reverse[buf[3]] << 12); yading@10: buf += 6; yading@10: } yading@10: } else { yading@10: uint16_t *o = (uint16_t *)frame->data[0]; yading@10: for (; buf_size > 4; buf_size -= 5) { yading@10: *o++ = (ff_reverse[buf[1]] << 8) | yading@10: ff_reverse[buf[0]]; yading@10: *o++ = (ff_reverse[buf[4] & 0xf0] << 12) | yading@10: (ff_reverse[buf[3]] << 4) | yading@10: (ff_reverse[buf[2]] >> 4); yading@10: buf += 5; yading@10: } yading@10: } yading@10: yading@10: *got_frame_ptr = 1; yading@10: yading@10: return avpkt->size; yading@10: } yading@10: yading@10: AVCodec ff_s302m_decoder = { yading@10: .name = "s302m", yading@10: .type = AVMEDIA_TYPE_AUDIO, yading@10: .id = AV_CODEC_ID_S302M, yading@10: .decode = s302m_decode_frame, yading@10: .capabilities = CODEC_CAP_DR1, yading@10: .long_name = NULL_IF_CONFIG_SMALL("SMPTE 302M"), yading@10: };