asf.c.svn-base

mediastreamer2是开源的网络传输媒体流的库

            for(j = 0; j < stream_count; j++) {
                int flags, bitrate, stream_id;

                flags= get_le16(pb);
                bitrate= get_le32(pb);
                stream_id= (flags & 0x7f);
//                av_log(NULL, AV_LOG_ERROR, "flags: 0x%x stream id %d, bitrate %d\n", flags, stream_id, bitrate);
                asf->stream_bitrates[stream_id]= bitrate;
            }
       } else if (!memcmp(&g, &extended_content_header, sizeof(GUID))) {
                int desc_count, i;

                desc_count = get_le16(pb);
                for(i=0;i<desc_count;i++)
                {
                        int name_len,value_type,value_len;
                        uint64_t value_num = 0;
                        char name[1024];

                        name_len = get_le16(pb);
                        get_str16_nolen(pb, name_len, name, sizeof(name));
                        value_type = get_le16(pb);
                        value_len = get_le16(pb);
                        if ((value_type == 0) || (value_type == 1)) // unicode or byte
                        {
                                if     (!strcmp(name,"WM/AlbumTitle")) get_str16_nolen(pb, value_len, s->album, sizeof(s->album));
                                else if(!strcmp(name,"WM/Genre"     )) get_str16_nolen(pb, value_len, s->genre, sizeof(s->genre));
                                else if(!strcmp(name,"WM/Year"      )) {
                                    char year[8];
                                    get_str16_nolen(pb, value_len, year, sizeof(year));
                                    s->year = atoi(year);
                                }
                                else if(!strcmp(name,"WM/Track") && s->track == 0) {
                                    char track[8];
                                    get_str16_nolen(pb, value_len, track, sizeof(track));
                                    s->track = strtol(track, NULL, 10) + 1;
                                }
                                else if(!strcmp(name,"WM/TrackNumber")) {
                                    char track[8];
                                    get_str16_nolen(pb, value_len, track, sizeof(track));
                                    s->track = strtol(track, NULL, 10);
                                }
                                else url_fskip(pb, value_len);
                        }
                        if ((value_type >= 2) && (value_type <= 5)) // boolean or DWORD or QWORD or WORD
                        {
                                value_num= get_value(pb, value_type);
                                if (!strcmp(name,"WM/Track"      ) && s->track == 0) s->track = value_num + 1;
                                if (!strcmp(name,"WM/TrackNumber")) s->track = value_num;
                        }
                }
        } else if (!memcmp(&g, &metadata_header, sizeof(GUID))) {
            int n, stream_num, name_len, value_len, value_type, value_num;
            n = get_le16(pb);

            for(i=0;i<n;i++) {
                char name[1024];

                get_le16(pb); //lang_list_index
                stream_num= get_le16(pb);
                name_len=   get_le16(pb);
                value_type= get_le16(pb);
                value_len=  get_le32(pb);

                get_str16_nolen(pb, name_len, name, sizeof(name));
//av_log(NULL, AV_LOG_ERROR, "%d %d %d %d %d <%s>\n", i, stream_num, name_len, value_type, value_len, name);
                value_num= get_le16(pb);//we should use get_value() here but it does not work 2 is le16 here but le32 elsewhere
                url_fskip(pb, value_len - 2);

                if(stream_num<128){
                    if     (!strcmp(name, "AspectRatioX")) dar[stream_num].num= value_num;
                    else if(!strcmp(name, "AspectRatioY")) dar[stream_num].den= value_num;
                }
            }
        } else if (!memcmp(&g, &ext_stream_header, sizeof(GUID))) {
            int ext_len, payload_ext_ct, stream_ct;
            uint32_t ext_d, leak_rate, stream_num;
            int64_t pos_ex_st;
            pos_ex_st = url_ftell(pb);

            get_le64(pb); // starttime
            get_le64(pb); // endtime
            leak_rate = get_le32(pb); // leak-datarate
            get_le32(pb); // bucket-datasize
            get_le32(pb); // init-bucket-fullness
            get_le32(pb); // alt-leak-datarate
            get_le32(pb); // alt-bucket-datasize
            get_le32(pb); // alt-init-bucket-fullness
            get_le32(pb); // max-object-size
            get_le32(pb); // flags (reliable,seekable,no_cleanpoints?,resend-live-cleanpoints, rest of bits reserved)
            stream_num = get_le16(pb); // stream-num
            get_le16(pb); // stream-language-id-index
            get_le64(pb); // avg frametime in 100ns units
            stream_ct = get_le16(pb); //stream-name-count
            payload_ext_ct = get_le16(pb); //payload-extension-system-count

            if (stream_num < 128)
                bitrate[stream_num] = leak_rate;

            for (i=0; i<stream_ct; i++){
                get_le16(pb);
                ext_len = get_le16(pb);
                url_fseek(pb, ext_len, SEEK_CUR);
            }

            for (i=0; i<payload_ext_ct; i++){
                get_guid(pb, &g);
                ext_d=get_le16(pb);
                ext_len=get_le32(pb);
                url_fseek(pb, ext_len, SEEK_CUR);
            }

            // there could be a optional stream properties object to follow
            // if so the next iteration will pick it up
        } else if (!memcmp(&g, &head1_guid, sizeof(GUID))) {
            int v1, v2;
            get_guid(pb, &g);
            v1 = get_le32(pb);
            v2 = get_le16(pb);
#if 0
        } else if (!memcmp(&g, &codec_comment_header, sizeof(GUID))) {
            int len, v1, n, num;
            char str[256], *q;
            char tag[16];

            get_guid(pb, &g);
            print_guid(&g);

            n = get_le32(pb);
            for(i=0;i<n;i++) {
                num = get_le16(pb); /* stream number */
                get_str16(pb, str, sizeof(str));
                get_str16(pb, str, sizeof(str));
                len = get_le16(pb);
                q = tag;
                while (len > 0) {
                    v1 = get_byte(pb);
                    if ((q - tag) < sizeof(tag) - 1)
                        *q++ = v1;
                    len--;
                }
                *q = '\0';
            }
#endif
        } else if (url_feof(pb)) {
            goto fail;
        } else {
            url_fseek(pb, gsize - 24, SEEK_CUR);
        }
    }
    get_guid(pb, &g);
    get_le64(pb);
    get_byte(pb);
    get_byte(pb);
    if (url_feof(pb))
        goto fail;
    asf->data_offset = url_ftell(pb);
    asf->packet_size_left = 0;


    for(i=0; i<128; i++){
        int stream_num= asf->asfid2avid[i];
        if(stream_num>=0){
            AVCodecContext *codec= s->streams[stream_num]->codec;
            if (!codec->bit_rate)
                codec->bit_rate = bitrate[i];
            if (dar[i].num > 0 && dar[i].den > 0)
                av_reduce(&codec->sample_aspect_ratio.num,
                          &codec->sample_aspect_ratio.den,
                          dar[i].num, dar[i].den, INT_MAX);
//av_log(NULL, AV_LOG_ERROR, "dar %d:%d sar=%d:%d\n", dar[i].num, dar[i].den, codec->sample_aspect_ratio.num, codec->sample_aspect_ratio.den);
        }
    }

    return 0;

 fail:
     for(i=0;i<s->nb_streams;i++) {
        AVStream *st = s->streams[i];
        if (st) {
            av_free(st->priv_data);
            av_free(st->codec->extradata);
        }
        av_free(st);
    }
    return -1;
}

#define DO_2BITS(bits, var, defval) \
    switch (bits & 3) \
    { \
    case 3: var = get_le32(pb); rsize += 4; break; \
    case 2: var = get_le16(pb); rsize += 2; break; \
    case 1: var = get_byte(pb); rsize++; break; \
    default: var = defval; break; \
    }

/**
 *
 * @return <0 in case of an error
 */
static int asf_get_packet(AVFormatContext *s)
{
    ASFContext *asf = s->priv_data;
    ByteIOContext *pb = s->pb;
    uint32_t packet_length, padsize;
    int rsize = 8;
    int c, d, e, off;

    off= (url_ftell(s->pb) - s->data_offset) % asf->packet_size + 3;

    c=d=e=-1;
    while(off-- > 0){
        c=d; d=e;
        e= get_byte(pb);
        if(c == 0x82 && !d && !e)
            break;
    }

    if (c != 0x82) {
        if (!url_feof(pb))
            av_log(s, AV_LOG_ERROR, "ff asf bad header %x  at:%"PRId64"\n", c, url_ftell(pb));
    }
    if ((c & 0x8f) == 0x82) {
        if (d || e) {
            if (!url_feof(pb))
                av_log(s, AV_LOG_ERROR, "ff asf bad non zero\n");
            return -1;
        }
        c= get_byte(pb);
        d= get_byte(pb);
        rsize+=3;
    }else{
        url_fseek(pb, -1, SEEK_CUR); //FIXME
    }

    asf->packet_flags    = c;
    asf->packet_property = d;

    DO_2BITS(asf->packet_flags >> 5, packet_length, asf->packet_size);
    DO_2BITS(asf->packet_flags >> 1, padsize, 0); // sequence ignored
    DO_2BITS(asf->packet_flags >> 3, padsize, 0); // padding length

    //the following checks prevent overflows and infinite loops
    if(packet_length >= (1U<<29)){
        av_log(s, AV_LOG_ERROR, "invalid packet_length %d at:%"PRId64"\n", packet_length, url_ftell(pb));
        return -1;
    }
    if(padsize >= packet_length){
        av_log(s, AV_LOG_ERROR, "invalid padsize %d at:%"PRId64"\n", padsize, url_ftell(pb));
        return -1;
    }

    asf->packet_timestamp = get_le32(pb);
    get_le16(pb); /* duration */
    // rsize has at least 11 bytes which have to be present

    if (asf->packet_flags & 0x01) {
        asf->packet_segsizetype = get_byte(pb); rsize++;
        asf->packet_segments = asf->packet_segsizetype & 0x3f;
    } else {
        asf->packet_segments = 1;
        asf->packet_segsizetype = 0x80;
    }
    asf->packet_size_left = packet_length - padsize - rsize;
    if (packet_length < asf->hdr.min_pktsize)
        padsize += asf->hdr.min_pktsize - packet_length;
    asf->packet_padsize = padsize;
#ifdef DEBUG
    printf("packet: size=%d padsize=%d  left=%d\n", asf->packet_size, asf->packet_padsize, asf->packet_size_left);
#endif
    return 0;
}

/**
 *
 * @return <0 if error
 */
static int asf_read_frame_header(AVFormatContext *s){
    ASFContext *asf = s->priv_data;
    ByteIOContext *pb = s->pb;
    int rsize = 1;
    int num = get_byte(pb);
    int64_t ts0, ts1;

    asf->packet_segments--;
    asf->packet_key_frame = num >> 7;
    asf->stream_index = asf->asfid2avid[num & 0x7f];
    // sequence should be ignored!
    DO_2BITS(asf->packet_property >> 4, asf->packet_seq, 0);
    DO_2BITS(asf->packet_property >> 2, asf->packet_frag_offset, 0);
    DO_2BITS(asf->packet_property, asf->packet_replic_size, 0);
//printf("key:%d stream:%d seq:%d offset:%d replic_size:%d\n", asf->packet_key_frame, asf->stream_index, asf->packet_seq, //asf->packet_frag_offset, asf->packet_replic_size);
    if (asf->packet_replic_size >= 8) {
        asf->packet_obj_size = get_le32(pb);
        if(asf->packet_obj_size >= (1<<24) || asf->packet_obj_size <= 0){
            av_log(s, AV_LOG_ERROR, "packet_obj_size invalid\n");
            return -1;
        }
        asf->packet_frag_timestamp = get_le32(pb); // timestamp
        if(asf->packet_replic_size >= 8+38+4){
//            for(i=0; i<asf->packet_replic_size-8; i++)
//                av_log(s, AV_LOG_DEBUG, "%02X ",get_byte(pb));
//            av_log(s, AV_LOG_DEBUG, "\n");
            url_fskip(pb, 10);
            ts0= get_le64(pb);
            ts1= get_le64(pb);
            url_fskip(pb, 12);
            get_le32(pb);
            url_fskip(pb, asf->packet_replic_size - 8 - 38 - 4);
            if(ts0!= -1) asf->packet_frag_timestamp= ts0/10000;
            else         asf->packet_frag_timestamp= AV_NOPTS_VALUE;
        }else
            url_fskip(pb, asf->packet_replic_size - 8);
        rsize += asf->packet_replic_size; // FIXME - check validity
    } else if (asf->packet_replic_size==1){
        // multipacket - frag_offset is beginning timestamp
        asf->packet_time_start = asf->packet_frag_offset;
        asf->packet_frag_offset = 0;
        asf->packet_frag_timestamp = asf->packet_timestamp;

        asf->packet_time_delta = get_byte(pb);
        rsize++;
    }else if(asf->packet_replic_size!=0){
        av_log(s, AV_LOG_ERROR, "unexpected packet_replic_size of %d\n", asf->packet_replic_size);
        return -1;
    }
    if (asf->packet_flags & 0x01) {
        DO_2BITS(asf->packet_segsizetype >> 6, asf->packet_frag_size, 0); // 0 is illegal
        if(asf->packet_frag_size > asf->packet_size_left - rsize){
            av_log(s, AV_LOG_ERROR, "packet_frag_size is invalid\n");
            return -1;
        }
        //printf("Fragsize %d\n", asf->packet_frag_size);
    } else {
        asf->packet_frag_size = asf->packet_size_left - rsize;
        //printf("Using rest  %d %d %d\n", asf->packet_frag_size, asf->packet_size_left, rsize);
    }
    if (asf->packet_replic_size == 1) {
        asf->packet_multi_size = asf->packet_frag_size;
        if (asf->packet_multi_size > asf->packet_size_left)
            return -1;
    }
    asf->packet_size_left -= rsize;
    //printf("___objsize____  %d   %d    rs:%d\n", asf->packet_obj_size, asf->packet_frag_offset, rsize);

    return 0;
}

static int asf_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    ASFContext *asf = s->priv_data;
    ASFStream *asf_st = 0;
    ByteIOContext *pb = s->pb;
    //static int pc = 0;
    for (;;) {
        if(url_feof(pb))
            return AVERROR(EIO);
        if (asf->packet_size_left < FRAME_HEADER_SIZE
            || asf->packet_segments < 1) {
            //asf->packet_size_left <= asf->packet_padsize) {
            int ret = asf->packet_size_left + asf->packet_padsize;
            //printf("PacketLeftSize:%d  Pad:%d Pos:%"PRId64"\n", asf->packet_size_left, asf->packet_padsize, url_ftell(pb));
            assert(ret>=0);
            /* fail safe */
            url_fskip(pb, ret);

            asf->packet_pos= url_ftell(s->pb);