dv.c

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.10平台上编译为嵌入式图形界面操作系统。

	    fprintf(stderr, "Can't process DV frame #%d. Insufficient audio data or severe sync problem.\n", c->frames);
	    
        dv_inject_video(c, data, *frame);
	c->has_video = 1;
	data_size = 0;
    } 
    
    reqasize = 4 * dv_audio_frame_size(c->sys, c->frames);
    fsize = fifo_size(&c->audio_data, c->audio_data.rptr);
    if (st->codec.codec_type == CODEC_TYPE_AUDIO || (c->has_video && fsize >= reqasize)) { 
	if (fsize + data_size >= reqasize && !c->has_audio) {
            if (fsize >= reqasize) {
	        fifo_read(&c->audio_data, &pcm[0], reqasize, &c->audio_data.rptr);
            } else {
	        fifo_read(&c->audio_data, &pcm[0], fsize, &c->audio_data.rptr);
                memcpy(&pcm[fsize], &data[0], reqasize - fsize);
		data += reqasize - fsize;
		data_size -= reqasize - fsize;
	    }
	    dv_inject_audio(c, &pcm[0], *frame);
	    c->has_audio = 1;
	}
    
        /* FIXME: we have to have more sensible approach than this one */
        if (fifo_size(&c->audio_data, c->audio_data.rptr) + data_size >= 100*AVCODEC_MAX_AUDIO_FRAME_SIZE)
	    fprintf(stderr, "Can't process DV frame #%d. Insufficient video data or severe sync problem.\n", c->frames);
	fifo_write(&c->audio_data, (uint8_t *)data, data_size, &c->audio_data.wptr);
    }

    return (c->has_audio && c->has_video) ? c->sys->frame_size : 0;
}

DVMuxContext* dv_init_mux(AVFormatContext* s)
{
    DVMuxContext *c;
    AVStream *vst;
    AVStream *ast;

    c = av_mallocz(sizeof(DVMuxContext));
    if (!c)
        return NULL;

    if (s->nb_streams != 2)
        goto bail_out;

    /* We have to sort out where audio and where video stream is */
    if (s->streams[0]->codec.codec_type == CODEC_TYPE_VIDEO &&
        s->streams[1]->codec.codec_type == CODEC_TYPE_AUDIO) {
       vst = s->streams[0];
       ast = s->streams[1];
    }
    else if (s->streams[1]->codec.codec_type == CODEC_TYPE_VIDEO &&
             s->streams[0]->codec.codec_type == CODEC_TYPE_AUDIO) {
           vst = s->streams[1];
           ast = s->streams[0];
    } else
        goto bail_out;
  
    /* Some checks -- DV format is very picky about its incoming streams */
    if (vst->codec.codec_id != CODEC_ID_DVVIDEO ||
	ast->codec.codec_id != CODEC_ID_PCM_S16LE)
       goto bail_out;
    if (ast->codec.sample_rate != 48000 ||
	ast->codec.channels != 2)
       goto bail_out;

    c->sys = dv_codec_profile(&vst->codec);
    if (!c->sys)
	goto bail_out;
    
    /* Ok, everything seems to be in working order */
    c->frames = 0;
    c->has_audio = c->has_video = 0;
    c->start_time = time(NULL);
    c->aspect = 0; /* 4:3 is the default */
    if ((int)(av_q2d(vst->codec.sample_aspect_ratio) * vst->codec.width / vst->codec.height * 10) == 17) /* 16:9 */ 
        c->aspect = 0x07;

    if (fifo_init(&c->audio_data, 100*AVCODEC_MAX_AUDIO_FRAME_SIZE) < 0)
        goto bail_out;

    dv_format_frame(c, &c->frame_buf[0]);

    return c;
    
bail_out:
    av_free(c);
    return NULL;
}

void dv_delete_mux(DVMuxContext *c)
{    
    fifo_free(&c->audio_data);
}

DVDemuxContext* dv_init_demux(AVFormatContext *s)
{
    DVDemuxContext *c;

    c = av_mallocz(sizeof(DVDemuxContext));
    if (!c)
        return NULL;

    c->vst = av_new_stream(s, 0);
    c->ast[0] = av_new_stream(s, 0);
    if (!c->vst || !c->ast[0])
        goto fail;
    c->fctx = s;
    c->ast[1] = NULL;
    c->ach = 0;
    c->audio_pkt[0].size = 0;
    c->audio_pkt[1].size = 0;
    
    c->vst->codec.codec_type = CODEC_TYPE_VIDEO;
    c->vst->codec.codec_id = CODEC_ID_DVVIDEO;
    c->vst->codec.bit_rate = 25000000;
    
    c->ast[0]->codec.codec_type = CODEC_TYPE_AUDIO;
    c->ast[0]->codec.codec_id = CODEC_ID_PCM_S16LE;
   
    s->ctx_flags |= AVFMTCTX_NOHEADER; 
    
    return c;
    
fail:
    if (c->vst)
        av_free(c->vst);
    if (c->ast[0])
        av_free(c->ast[0]);
    av_free(c);
    return NULL;
}

static void __destruct_pkt(struct AVPacket *pkt)
{
    pkt->data = NULL; pkt->size = 0;
    return;
}

int dv_get_packet(DVDemuxContext *c, AVPacket *pkt)
{
    int size = -1;
    int i;

    for (i=0; i<c->ach; i++) {
       if (c->ast[i] && c->audio_pkt[i].size) {
           *pkt = c->audio_pkt[i];
	   c->audio_pkt[i].size = 0;
	   size = pkt->size;
	   break;
       }
    }

    return size;
}

int dv_produce_packet(DVDemuxContext *c, AVPacket *pkt, 
                      uint8_t* buf, int buf_size)
{
    int size, i;
   
    if (buf_size < 4 || buf_size < dv_frame_profile(buf)->frame_size)
        return -1;   /* Broken frame, or not enough data */

    /* Queueing audio packet */
    /* FIXME: in case of no audio/bad audio we have to do something */
    size = dv_extract_audio_info(c, buf);
    c->audio_pkt[0].data = c->audio_pkt[1].data = NULL;
    for (i=0; i<c->ach; i++) {
       if (av_new_packet(&c->audio_pkt[i], size) < 0)
           return AVERROR_NOMEM;
       c->audio_pkt[i].stream_index = c->ast[i]->index;
    }
    dv_extract_audio(buf, c->audio_pkt[0].data, c->audio_pkt[1].data);
    
    /* Now it's time to return video packet */
    size = dv_extract_video_info(c, buf);
    av_init_packet(pkt);
    pkt->destruct = __destruct_pkt;
    pkt->data     = buf;
    pkt->size     = size; 
    pkt->flags   |= PKT_FLAG_KEY;
    pkt->stream_index = c->vst->id;

    return size;
}
                           
/************************************************************
 * Implementation of the easiest DV storage of all -- raw DV.
 ************************************************************/
 
typedef struct RawDVContext {
    uint8_t         buf[144000];
    DVDemuxContext* dv_demux;
} RawDVContext;

static int dv_read_header(AVFormatContext *s,
                          AVFormatParameters *ap)
{
    RawDVContext *c = s->priv_data;
    c->dv_demux = dv_init_demux(s);
   
    return c->dv_demux ? 0 : -1;
}


static int dv_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    int size;
    RawDVContext *c = s->priv_data; 
  
    size = dv_get_packet(c->dv_demux, pkt);
    
    if (size < 0) {
        if (get_buffer(&s->pb, c->buf, 4) <= 0) 
            return -EIO;
    
        size = dv_frame_profile(c->buf)->frame_size;
        if (get_buffer(&s->pb, c->buf + 4, size - 4) <= 0)
	    return -EIO;

	size = dv_produce_packet(c->dv_demux, pkt, c->buf, size);
    } 
    
    return size;
}

static int dv_read_close(AVFormatContext *s)
{
    RawDVContext *c = s->priv_data;
    av_free(c->dv_demux);
    return 0;
}

static int dv_write_header(AVFormatContext *s)
{
    s->priv_data = dv_init_mux(s);
    if (!s->priv_data) {
        fprintf(stderr, "Can't initialize DV format!\n"
		    "Make sure that you supply exactly two streams:\n"
		    "     video: 25fps or 29.97fps, audio: 2ch/48Khz/PCM\n");
	return -1;
    }
    return 0;
}

static int dv_write_packet(struct AVFormatContext *s, 
                           int stream_index,
                           const uint8_t *buf, int size, int64_t pts)
{
    uint8_t* frame;
    int fsize;
   
    fsize = dv_assemble_frame((DVMuxContext *)s->priv_data, s->streams[stream_index],
                              buf, size, &frame);
    if (fsize > 0) {
        put_buffer(&s->pb, frame, fsize); 
        put_flush_packet(&s->pb);
    } 
    return fsize;
}

/* 
 * We might end up with some extra A/V data without matching counterpart.
 * E.g. video data without enough audio to write the complete frame.
 * Currently we simply drop the last frame. I don't know whether this 
 * is the best strategy of all
 */
static int dv_write_trailer(struct AVFormatContext *s)
{
    dv_delete_mux((DVMuxContext *)s->priv_data);
    return 0;
}

static AVInputFormat dv_iformat = {
    "dv",
    "DV video format",
    sizeof(RawDVContext),
    NULL,
    dv_read_header,
    dv_read_packet,
    dv_read_close,
    .extensions = "dv",
};

static AVOutputFormat dv_oformat = {
    "dv",
    "DV video format",
    NULL,
    "dv",
    sizeof(DVMuxContext),
    CODEC_ID_PCM_S16LE,
    CODEC_ID_DVVIDEO,
    dv_write_header,
    dv_write_packet,
    dv_write_trailer,
};

int dv_init(void)
{
    av_register_input_format(&dv_iformat);
    av_register_output_format(&dv_oformat);
    return 0;
}