utils.c

mpeg4 video codec mpeg4 video codec

    }
  }
 fail:
    return ret;
}

/* absolute maximum size we read until we abort */
#define MAX_READ_SIZE        5000000

/* maximum duration until we stop analysing the stream */
#define MAX_STREAM_DURATION  ((int)(AV_TIME_BASE * 2.0))


/*******************************************************/

/**
 * start playing a network based stream (e.g. RTSP stream) at the
 * current position 
 */
int av_read_play(AVFormatContext *s)
{
    if (!s->iformat->read_play)
        return AVERROR_NOTSUPP;
    return s->iformat->read_play(s);
}

/**
 * Pause a network based stream (e.g. RTSP stream).
 *
 * Use av_read_play() to resume it.
 */
int av_read_pause(AVFormatContext *s)
{
    if (!s->iformat->read_pause)
        return AVERROR_NOTSUPP;
    return s->iformat->read_pause(s);
}

/**
 * Close a media file (but not its codecs).
 *
 * @param s media file handle
 */
void av_close_input_file(AVFormatContext *s)
{
    int i, must_open_file;
    AVStream *st;

    /* free previous packet */
    if (s->cur_st && s->cur_st->parser)
        av_free_packet(&s->cur_pkt); 

    if (s->iformat->read_close)
        s->iformat->read_close(s);
    for(i=0;i<s->nb_streams;i++) {
        /* free all data in a stream component */
        st = s->streams[i];
        if (st->parser) {
            av_parser_close(st->parser);
        }
        av_free(st->index_entries);
        av_free(st->codec);
        av_free(st);
    }
    flush_packet_queue(s);
    must_open_file = 1;
    if (s->iformat->flags & AVFMT_NOFILE) {
        must_open_file = 0;
    }
    if (must_open_file) {
        url_fclose(&s->pb);
    }
    av_freep(&s->priv_data);
    av_free(s);
}

/**
 * Add a new stream to a media file.
 *
 * Can only be called in the read_header() function. If the flag
 * AVFMTCTX_NOHEADER is in the format context, then new streams
 * can be added in read_packet too.
 *
 * @param s media file handle
 * @param id file format dependent stream id 
 */
AVStream *av_new_stream(AVFormatContext *s, int id)
{
    AVStream *st;

    if (s->nb_streams >= MAX_STREAMS)
        return NULL;

    st = av_mallocz(sizeof(AVStream));
    if (!st)
        return NULL;
    
    st->codec= avcodec_alloc_context();
    if (s->iformat) {
        /* no default bitrate if decoding */
        st->codec->bit_rate = 0;
    }
    st->index = s->nb_streams;
    st->id = id;
    st->start_time = AV_NOPTS_VALUE;
    st->duration = AV_NOPTS_VALUE;
    st->cur_dts = AV_NOPTS_VALUE;

    /* default pts settings is MPEG like */
    av_set_pts_info(st, 33, 1, 90000);
    st->last_IP_pts = AV_NOPTS_VALUE;

    s->streams[s->nb_streams++] = st;
    return st;
}

/************************************************************/
/* output media file */

int av_set_parameters(AVFormatContext *s, AVFormatParameters *ap)
{
    int ret;

    if (s->oformat->priv_data_size > 0) {
    s->priv_data = av_mallocz(s->oformat->priv_data_size);
    if (!s->priv_data)
        return AVERROR_NOMEM;
    } else
        s->priv_data = NULL;
	
    if (s->oformat->set_parameters) {
        ret = s->oformat->set_parameters(s, ap);
        if (ret < 0)
            return ret;
    }
    return 0;
}

/**
 * allocate the stream private data and write the stream header to an
 * output media file
 *
 * @param s media file handle
 * @return 0 if OK. AVERROR_xxx if error.  
 */
int av_write_header(AVFormatContext *s)
{
    int ret, i;
    AVStream *st;

    // some sanity checks
    for(i=0;i<s->nb_streams;i++) {
        st = s->streams[i];

        switch (st->codec->codec_type) {
        case CODEC_TYPE_AUDIO:
            if(st->codec->sample_rate<=0){
                av_log(s, AV_LOG_ERROR, "sample rate not set\n");
                return -1;
            }
            break;
        case CODEC_TYPE_VIDEO:
            if(st->codec->time_base.num<=0 || st->codec->time_base.den<=0){ //FIXME audio too?
                av_log(s, AV_LOG_ERROR, "time base not set\n");
                return -1;
            }
            if(st->codec->width<=0 || st->codec->height<=0){
                av_log(s, AV_LOG_ERROR, "dimensions not set\n");
                return -1;
            }
            break;
        }
    }

    ret = s->oformat->write_header(s);
    if (ret < 0)
        return ret;

    /* init PTS generation */
    for(i=0;i<s->nb_streams;i++) {
        int64_t den = AV_NOPTS_VALUE;
        st = s->streams[i];

        switch (st->codec->codec_type) {
        case CODEC_TYPE_AUDIO:
            den = (int64_t)st->time_base.num * st->codec->sample_rate;
            break;
        case CODEC_TYPE_VIDEO:
            den = (int64_t)st->time_base.num * st->codec->time_base.den;
            break;
        default:
            break;
        }
        if (den != AV_NOPTS_VALUE) {
            if (den <= 0)
                return AVERROR_INVALIDDATA;
            av_frac_init(&st->pts, 0, 0, den);
        }
    }
    return 0;
}

//FIXME merge with compute_pkt_fields
static int compute_pkt_fields2(AVStream *st, AVPacket *pkt){
    int b_frames = FFMAX(st->codec->has_b_frames, st->codec->max_b_frames);
    int num, den, frame_size;

//    av_log(NULL, AV_LOG_DEBUG, "av_write_frame: pts:%lld dts:%lld cur_dts:%lld b:%d size:%d st:%d\n", pkt->pts, pkt->dts, st->cur_dts, b_frames, pkt->size, pkt->stream_index);
    
/*    if(pkt->pts == AV_NOPTS_VALUE && pkt->dts == AV_NOPTS_VALUE)
        return -1;*/
            
    /* duration field */
    if (pkt->duration == 0) {
        compute_frame_duration(&num, &den, st, NULL, pkt);
        if (den && num) {
            pkt->duration = av_rescale(1, num * (int64_t)st->time_base.den, den * (int64_t)st->time_base.num);
        }
    }

    //XXX/FIXME this is a temporary hack until all encoders output pts
    if((pkt->pts == 0 || pkt->pts == AV_NOPTS_VALUE) && pkt->dts == AV_NOPTS_VALUE && !b_frames){
        pkt->dts=
//        pkt->pts= st->cur_dts;
        pkt->pts= st->pts.val;
    }

    //calculate dts from pts    
    if(pkt->pts != AV_NOPTS_VALUE && pkt->dts == AV_NOPTS_VALUE){
        if(b_frames){
            if(st->last_IP_pts == AV_NOPTS_VALUE){
                st->last_IP_pts= -pkt->duration;
            }
            if(st->last_IP_pts < pkt->pts){
                pkt->dts= st->last_IP_pts;
                st->last_IP_pts= pkt->pts;
            }else
                pkt->dts= pkt->pts;
        }else
            pkt->dts= pkt->pts;
    }
    
    if(st->cur_dts && st->cur_dts != AV_NOPTS_VALUE && st->cur_dts >= pkt->dts){
        av_log(NULL, AV_LOG_ERROR, "error, non monotone timestamps %"PRId64" >= %"PRId64"\n", st->cur_dts, pkt->dts);
        return -1;
    }
    if(pkt->dts != AV_NOPTS_VALUE && pkt->pts != AV_NOPTS_VALUE && pkt->pts < pkt->dts){
        av_log(NULL, AV_LOG_ERROR, "error, pts < dts\n");
        return -1;
    }

//    av_log(NULL, AV_LOG_DEBUG, "av_write_frame: pts2:%lld dts2:%lld\n", pkt->pts, pkt->dts);
    st->cur_dts= pkt->dts;
    st->pts.val= pkt->dts;

    /* update pts */
    switch (st->codec->codec_type) {
    case CODEC_TYPE_AUDIO:
        frame_size = get_audio_frame_size(st->codec, pkt->size);

        /* HACK/FIXME, we skip the initial 0-size packets as they are most likely equal to the encoder delay,
           but it would be better if we had the real timestamps from the encoder */
        if (frame_size >= 0 && (pkt->size || st->pts.num!=st->pts.den>>1 || st->pts.val)) {
            av_frac_add(&st->pts, (int64_t)st->time_base.den * frame_size);
        }
        break;
    case CODEC_TYPE_VIDEO:
        av_frac_add(&st->pts, (int64_t)st->time_base.den * st->codec->time_base.num);
        break;
    default:
        break;
    }
    return 0;
}

static void truncate_ts(AVStream *st, AVPacket *pkt){
    int64_t pts_mask = (2LL << (st->pts_wrap_bits-1)) - 1;
    
//    if(pkt->dts < 0)
//        pkt->dts= 0;  //this happens for low_delay=0 and b frames, FIXME, needs further invstigation about what we should do here
    
    pkt->pts &= pts_mask;
    pkt->dts &= pts_mask;
}

/**
 * Write a packet to an output media file.
 *
 * The packet shall contain one audio or video frame.
 *
 * @param s media file handle
 * @param pkt the packet, which contains the stream_index, buf/buf_size, dts/pts, ...
 * @return < 0 if error, = 0 if OK, 1 if end of stream wanted.
 */
int av_write_frame(AVFormatContext *s, AVPacket *pkt)
{
    int ret;

    ret=compute_pkt_fields2(s->streams[pkt->stream_index], pkt);
    if (ret < 0)
        return ret;

    truncate_ts(s->streams[pkt->stream_index], pkt);

    ret= s->oformat->write_packet(s, pkt);
    if(!ret)
        ret= url_ferror(&s->pb);
    return ret;
}

/**
 * interleave_packet implementation which will interleave per DTS.
 * packets with pkt->destruct == av_destruct_packet will be freed inside this function. 
 * so they cannot be used after it, note calling av_free_packet() on them is still safe
 */
static int av_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out, AVPacket *pkt, int flush){
    AVPacketList *pktl, **next_point, *this_pktl;
    int stream_count=0;
    int streams[MAX_STREAMS];

    if(pkt){
        AVStream *st= s->streams[ pkt->stream_index];

//        assert(pkt->destruct != av_destruct_packet); //FIXME

        this_pktl = av_mallocz(sizeof(AVPacketList));
        this_pktl->pkt= *pkt;
        if(pkt->destruct == av_destruct_packet)
            pkt->destruct= NULL; // non shared -> must keep original from being freed
        else
            av_dup_packet(&this_pktl->pkt);  //shared -> must dup

        next_point = &s->packet_buffer;
        while(*next_point){
            AVStream *st2= s->streams[ (*next_point)->pkt.stream_index];
            int64_t left=  st2->time_base.num * (int64_t)st ->time_base.den;
            int64_t right= st ->time_base.num * (int64_t)st2->time_base.den;
            if((*next_point)->pkt.dts * left > pkt->dts * right) //FIXME this can overflow
                break;
            next_point= &(*next_point)->next;
        }
        this_pktl->next= *next_point;
        *next_point= this_pktl;
    }
    
    memset(streams, 0, sizeof(streams));
    pktl= s->packet_buffer;
    while(pktl){
//av_log(s, AV_LOG_DEBUG, "show st:%d dts:%lld\n", pktl->pkt.stream_index, pktl->pkt.dts);
        if(streams[ pktl->pkt.stream_index ] == 0)
            stream_count++;
        streams[ pktl->pkt.stream_index ]++;
        pktl= pktl->next;
            }
    
    if(s->nb_streams == stream_count || (flush && stream_count)){
        pktl= s->packet_buffer;
        *out= pktl->pkt;
        
        s->packet_buffer= pktl->next;        
        av_freep(&pktl);
        return 1;
        } else {
        av_init_packet(out);
        return 0;
    }
        }

/**
 * Interleaves a AVPacket correctly so it can be muxed.
 * @param out the interleaved packet will be output here
 * @param in the input packet
 * @param flush 1 if no further packets are available as input and all
 *              remaining packets should be output
 * @return 1 if a packet was output, 0 if no packet could be output, 
 *         < 0 if an error occured
 */
static int av_interleave_packet(AVFormatContext *s, AVPacket *out, AVPacket *in, int flush){
    if(s->oformat->interleave_packet)
        return s->oformat->interleave_packet(s, out, in, flush);
    else
        return av_interleave_packet_per_dts(s, out, in, flush);
    }

/**
 * Writes a packet to an output media file ensuring correct interleaving. 
 *
 * The packet must contain one audio or video frame.
 * If the packets are already correctly interleaved the application should
 * call av_write_frame() instead as its slightly faster, its also important
 * to keep in mind that completly non interleaved input will need huge amounts
 * of memory to interleave with this, so its prefereable to interleave at the
 * demuxer level
 *
 * @param s media file handle
 * @param pkt the packet, which contains the stream_index, buf/buf_size, dts/pts, ...
 * @return < 0 if error, = 0 if OK, 1 if end of stream wanted.
 */
int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt){
    AVStream *st= s->streams[ pkt->stream_index];

    //FIXME/XXX/HACK drop zero sized packets
    if(st->codec->codec_type == CODEC_TYPE_AUDIO && pkt->size==0)
        return 0;
    
//av_log(NULL, AV_LOG_DEBUG, "av_interleaved_write_frame %d %Ld %Ld\n", pkt->size, pkt->dts, pkt->pts);
    if(compute_pkt_fields2(st, pkt) < 0)
        return -1;
    
    if(pkt->dts == AV_NOPTS_VALUE)
        return -1;

    for(;;){
        AVPacket opkt;
        int ret= av_interleave_packet(s, &opkt, pkt, 0);
        if(ret<=0) //FIXME cleanup needed for ret<0 ?
    return ret;
        
        truncate_ts(s->streams[opkt.stream_index], &opkt);
        ret= s->oformat->write_packet(s, &opkt);
        
        av_free_packet(&opkt);
        pkt= NULL;
        
        if(ret<0)
            return ret;
        if(url_ferror(&s->pb))
            return url_ferror(&s->pb);
    }
}

/**
 * @brief Write the stream trailer to an output media file and
 *        free the file private data.
 *
 * @param s media file handle
 * @return 0 if OK. AVERROR_xxx if error.
 */
int av_write_trailer(AVFormatContext *s)
{
    int ret, i;
    
    for(;;){
        AVPacket pkt;
        ret= av_interleave_pac