231 lines
		
	
	
		
			7.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			231 lines
		
	
	
		
			7.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
 | 
						|
 * SMPTE 302M decoder
 | 
						|
 * Copyright (c) 2008 Laurent Aimar <fenrir@videolan.org>
 | 
						|
 * Copyright (c) 2009 Baptiste Coudurier <baptiste.coudurier@gmail.com>
 | 
						|
 *
 | 
						|
 * 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/intreadwrite.h"
 | 
						|
#include "libavutil/opt.h"
 | 
						|
#include "libavutil/log.h"
 | 
						|
#include "avcodec.h"
 | 
						|
#include "internal.h"
 | 
						|
#include "mathops.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;
 | 
						|
 | 
						|
    avctx->channels    = channels;
 | 
						|
    switch(channels) {
 | 
						|
        case 2:
 | 
						|
            avctx->channel_layout = AV_CH_LAYOUT_STEREO;
 | 
						|
            break;
 | 
						|
        case 4:
 | 
						|
            avctx->channel_layout = AV_CH_LAYOUT_QUAD;
 | 
						|
            break;
 | 
						|
        case 6:
 | 
						|
            avctx->channel_layout = AV_CH_LAYOUT_5POINT1_BACK;
 | 
						|
            break;
 | 
						|
        case 8:
 | 
						|
            avctx->channel_layout = AV_CH_LAYOUT_5POINT1_BACK | AV_CH_LAYOUT_STEREO_DOWNMIX;
 | 
						|
    }
 | 
						|
 | 
						|
    return frame_size;
 | 
						|
}
 | 
						|
 | 
						|
static int s302m_decode_frame(AVCodecContext *avctx, void *data,
 | 
						|
                              int *got_frame_ptr, AVPacket *avpkt)
 | 
						|
{
 | 
						|
    S302Context *s = avctx->priv_data;
 | 
						|
    AVFrame *frame     = data;
 | 
						|
    const uint8_t *buf = avpkt->data;
 | 
						|
    int buf_size       = avpkt->size;
 | 
						|
    int block_size, ret;
 | 
						|
    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;
 | 
						|
    frame->nb_samples = 2 * (buf_size / block_size) / avctx->channels;
 | 
						|
    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
 | 
						|
        return ret;
 | 
						|
 | 
						|
    avctx->bit_rate = 48000 * avctx->channels * (avctx->bits_per_raw_sample + 4) +
 | 
						|
                      32 * 48000 / frame->nb_samples;
 | 
						|
    buf_size = (frame->nb_samples * avctx->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++ = (ff_reverse[buf[2]]        << 24) |
 | 
						|
                   (ff_reverse[buf[1]]        << 16) |
 | 
						|
                   (ff_reverse[buf[0]]        <<  8);
 | 
						|
            *o++ = (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 (avctx->channels == 2)
 | 
						|
            for (i=0; i<frame->nb_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++ = (ff_reverse[buf[2] & 0xf0] << 28) |
 | 
						|
                   (ff_reverse[buf[1]]        << 20) |
 | 
						|
                   (ff_reverse[buf[0]]        << 12);
 | 
						|
            *o++ = (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 (avctx->channels == 2)
 | 
						|
            for (i=0; i<frame->nb_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 (avctx->channels == 2)
 | 
						|
            for (i=0; i<frame->nb_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_VIDEO_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 = {
 | 
						|
    "SMPTE 302M Decoder",
 | 
						|
    av_default_item_name,
 | 
						|
    s302m_options,
 | 
						|
    LIBAVUTIL_VERSION_INT,
 | 
						|
};
 | 
						|
 | 
						|
AVCodec ff_s302m_decoder = {
 | 
						|
    .name           = "s302m",
 | 
						|
    .long_name      = NULL_IF_CONFIG_SMALL("SMPTE 302M"),
 | 
						|
    .type           = AVMEDIA_TYPE_AUDIO,
 | 
						|
    .id             = AV_CODEC_ID_S302M,
 | 
						|
    .priv_data_size = sizeof(S302Context),
 | 
						|
    .decode         = s302m_decode_frame,
 | 
						|
    .capabilities   = AV_CODEC_CAP_DR1,
 | 
						|
    .priv_class     = &s302m_class,
 | 
						|
};
 |