dv.c

pmpmodavc102_sub_src,psp下很好的播放器源码

		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)
	    av_log(st->codec, AV_LOG_ERROR, "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);
    }

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

DVMuxContext* dv_init_mux(AVFormatContext* s)
{
    DVMuxContext *c;
    AVStream *vst = NULL;
    AVStream *ast = NULL;
    int i;

    if (s->nb_streams > 2)
        return NULL;

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

    /* We have to sort out where audio and where video stream is */
    for (i=0; i<s->nb_streams; i++) {
         switch (s->streams[i]->codec->codec_type) {
	 case CODEC_TYPE_VIDEO:
	       vst = s->streams[i];
	       break;
	 case CODEC_TYPE_AUDIO:
	       ast = s->streams[i];
	       break;
	 default:
	       goto bail_out;
	 }
    }
    
    /* Some checks -- DV format is very picky about its incoming streams */
    if (!vst || vst->codec->codec_id != CODEC_ID_DVVIDEO)
        goto bail_out;
    if (ast  && (ast->codec->codec_id != CODEC_ID_PCM_S16LE ||
	         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 = ast ? 0 : -1;
    c->has_video = 0;
    c->start_time = (time_t)s->timestamp;
    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 (ast && 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);
    if (!c->vst) {
        av_free(c);        
        return NULL;
    }

    c->fctx = s;
    c->ast[0] = c->ast[1] = NULL;
    c->ach = 0;
    c->frames = 0;
    c->abytes = 0;

    c->vst->codec->codec_type = CODEC_TYPE_VIDEO;
    c->vst->codec->codec_id = CODEC_ID_DVVIDEO;
    c->vst->codec->bit_rate = 25000000;
    c->vst->start_time = 0;
    
    return c;
}

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;
    const DVprofile* sys = dv_frame_profile(buf);
   
    if (buf_size < 4 || buf_size < sys->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);
    for (i=0; i<c->ach; i++) {
       c->audio_pkt[i].size = size;
       c->audio_pkt[i].pts  = c->abytes * 30000*8 / c->ast[i]->codec->bit_rate;
    }
    dv_extract_audio(buf, c->audio_buf[0], c->audio_buf[1]);
    c->abytes += size;
    
    /* Now it's time to return video packet */
    size = dv_extract_video_info(c, buf);
    av_init_packet(pkt);
    pkt->data     = buf;
    pkt->size     = size; 
    pkt->flags   |= PKT_FLAG_KEY;
    pkt->stream_index = c->vst->id;
    pkt->pts      = c->frames;
    
    c->frames++;

    return size;
}
                           
static int64_t dv_frame_offset(AVFormatContext *s, DVDemuxContext *c,
                              int64_t timestamp, int flags)
{
    // FIXME: sys may be wrong if last dv_read_packet() failed (buffer is junk)
    const DVprofile* sys = dv_codec_profile(c->vst->codec);
    int64_t offset;
    int64_t size = url_fsize(&s->pb);
    int64_t max_offset = ((size-1) / sys->frame_size) * sys->frame_size;

    offset = sys->frame_size * timestamp;
    
    if (offset > max_offset) offset = max_offset;
    else if (offset < 0) offset = 0;

    return offset;
}

void dv_flush_audio_packets(DVDemuxContext *c)
{
    c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
}

/************************************************************
 * 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;
    const DVprofile* sys;
    c->dv_demux = dv_init_demux(s);
    if (!c->dv_demux)
        return -1;
   
    if (get_buffer(&s->pb, c->buf, 4) <= 0 || url_fseek(&s->pb, -4, SEEK_CUR) < 0)
        return AVERROR_IO;

    sys = dv_frame_profile(c->buf);
    s->bit_rate = av_rescale(sys->frame_size * 8, sys->frame_rate, sys->frame_rate_base);
   
    return 0;
}


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 AVERROR_IO;
    
        size = dv_frame_profile(c->buf)->frame_size;
        if (get_buffer(&s->pb, c->buf + 4, size - 4) <= 0)
	    return AVERROR_IO;

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

static int dv_read_seek(AVFormatContext *s, int stream_index, 
                       int64_t timestamp, int flags)
{
    RawDVContext *r = s->priv_data;
    DVDemuxContext *c = r->dv_demux;
    int64_t offset= dv_frame_offset(s, c, timestamp, flags);
    const DVprofile* sys = dv_codec_profile(c->vst->codec);

    c->frames= offset / sys->frame_size;
    if (c->ach)
        c->abytes= av_rescale(c->frames,
                          c->ast[0]->codec->bit_rate * (int64_t)sys->frame_rate_base,
                          8*sys->frame_rate);
			  
    dv_flush_audio_packets(c);
    return url_fseek(&s->pb, offset, SEEK_SET);
}

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) {
        av_log(s, AV_LOG_ERROR, "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, AVPacket *pkt)
{
    uint8_t* frame;
    int fsize;
   
    fsize = dv_assemble_frame((DVMuxContext *)s->priv_data, s->streams[pkt->stream_index],
                              pkt->data, pkt->size, &frame);
    if (fsize > 0) {
        put_buffer(&s->pb, frame, fsize); 
        put_flush_packet(&s->pb);
    } 
    return 0;
}

/* 
 * 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,
    dv_read_seek,
    .extensions = "dv,dif",
};

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