rmdec.c

ffmpeg移植到symbian的全部源代码

        *pos= url_ftell(pb) - 3;
        if(rm->remaining_len > 0){
            num= rm->current_stream;
            len= rm->remaining_len;
            *timestamp = AV_NOPTS_VALUE;
            *flags= 0;
        }else{
            state= (state<<8) + get_byte(pb);

            if(state == MKBETAG('I', 'N', 'D', 'X')){
                len = get_be16(pb) - 6;
                if(len<0)
                    continue;
                goto skip;
            }

            if(state > (unsigned)0xFFFF || state < 12)
                continue;
            len=state;
            state= 0xFFFFFFFF;

            num = get_be16(pb);
            *timestamp = get_be32(pb);
            res= get_byte(pb); /* reserved */
            *flags = get_byte(pb); /* flags */


            len -= 12;
        }
        for(i=0;i<s->nb_streams;i++) {
            st = s->streams[i];
            if (num == st->id)
                break;
        }
        if (i == s->nb_streams) {
skip:
            /* skip packet if unknown number */
            url_fskip(pb, len);
            rm->remaining_len -= len;
            continue;
        }
        *stream_index= i;

        return len;
    }
    return -1;
}

static int rm_assemble_video_frame(AVFormatContext *s, RMContext *rm, AVPacket *pkt, int len)
{
    ByteIOContext *pb = s->pb;
    int hdr, seq, pic_num, len2, pos;
    int type;

    hdr = get_byte(pb); len--;
    type = hdr >> 6;
    switch(type){
    case 0: // slice
    case 2: // last slice
        seq = get_byte(pb); len--;
        len2 = get_num(pb, &len);
        pos = get_num(pb, &len);
        pic_num = get_byte(pb); len--;
        rm->remaining_len = len;
        break;
    case 1: //whole frame
        seq = get_byte(pb); len--;
        if(av_new_packet(pkt, len + 9) < 0)
            return AVERROR(EIO);
        pkt->data[0] = 0;
        AV_WL32(pkt->data + 1, 1);
        AV_WL32(pkt->data + 5, 0);
        get_buffer(pb, pkt->data + 9, len);
        rm->remaining_len = 0;
        return 0;
    case 3: //frame as a part of packet
        len2 = get_num(pb, &len);
        pos = get_num(pb, &len);
        pic_num = get_byte(pb); len--;
        rm->remaining_len = len - len2;
        if(av_new_packet(pkt, len2 + 9) < 0)
            return AVERROR(EIO);
        pkt->data[0] = 0;
        AV_WL32(pkt->data + 1, 1);
        AV_WL32(pkt->data + 5, 0);
        get_buffer(pb, pkt->data + 9, len2);
        return 0;
    }
    //now we have to deal with single slice

    if((seq & 0x7F) == 1 || rm->curpic_num != pic_num){
        rm->slices = ((hdr & 0x3F) << 1) + 1;
        rm->videobufsize = len2 + 8*rm->slices + 1;
        av_free(rm->videobuf);
        if(!(rm->videobuf = av_malloc(rm->videobufsize)))
            return AVERROR(ENOMEM);
        rm->videobufpos = 8*rm->slices + 1;
        rm->cur_slice = 0;
        rm->curpic_num = pic_num;
        rm->pktpos = url_ftell(pb);
    }
    if(type == 2)
        len = FFMIN(len, pos);

    if(++rm->cur_slice > rm->slices)
        return 1;
    AV_WL32(rm->videobuf - 7 + 8*rm->cur_slice, 1);
    AV_WL32(rm->videobuf - 3 + 8*rm->cur_slice, rm->videobufpos - 8*rm->slices - 1);
    if(rm->videobufpos + len > rm->videobufsize)
        return 1;
    if (get_buffer(pb, rm->videobuf + rm->videobufpos, len) != len)
        return AVERROR(EIO);
    rm->videobufpos += len;
    rm->remaining_len-= len;

    if(type == 2 || (rm->videobufpos) == rm->videobufsize){
         rm->videobuf[0] = rm->cur_slice-1;
         if(av_new_packet(pkt, rm->videobufpos - 8*(rm->slices - rm->cur_slice)) < 0)
             return AVERROR(ENOMEM);
         memcpy(pkt->data, rm->videobuf, 1 + 8*rm->cur_slice);
         memcpy(pkt->data + 1 + 8*rm->cur_slice, rm->videobuf + 1 + 8*rm->slices,
                rm->videobufpos - 1 - 8*rm->slices);
         pkt->pts = AV_NOPTS_VALUE;
         pkt->pos = rm->pktpos;
         return 0;
    }

    return 1;
}

static inline void
rm_ac3_swap_bytes (AVStream *st, AVPacket *pkt)
{
    uint8_t *ptr;
    int j;

    if (st->codec->codec_id == CODEC_ID_AC3) {
        ptr = pkt->data;
        for (j=0;j<pkt->size;j+=2) {
            FFSWAP(int, ptr[0], ptr[1]);
            ptr += 2;
        }
    }
}

int
ff_rm_parse_packet (AVFormatContext *s, AVStream *st, int len, AVPacket *pkt,
                    int *seq, int *flags, int64_t *timestamp)
{
    ByteIOContext *pb = s->pb;
    RMContext *rm = s->priv_data;

    if (st->codec->codec_type == CODEC_TYPE_VIDEO) {
        rm->current_stream= st->id;
        if(rm_assemble_video_frame(s, rm, pkt, len) == 1)
            return -1; //got partial frame
    } else if (st->codec->codec_type == CODEC_TYPE_AUDIO) {
        if ((st->codec->codec_id == CODEC_ID_RA_288) ||
            (st->codec->codec_id == CODEC_ID_COOK) ||
            (st->codec->codec_id == CODEC_ID_ATRAC3)) {
            int x;
            int sps = rm->sub_packet_size;
            int cfs = rm->coded_framesize;
            int h = rm->sub_packet_h;
            int y = rm->sub_packet_cnt;
            int w = rm->audio_framesize;

            if (*flags & 2)
                y = rm->sub_packet_cnt = 0;
            if (!y)
                rm->audiotimestamp = *timestamp;

            switch(st->codec->codec_id) {
                case CODEC_ID_RA_288:
                    for (x = 0; x < h/2; x++)
                        get_buffer(pb, rm->audiobuf+x*2*w+y*cfs, cfs);
                    break;
                case CODEC_ID_ATRAC3:
                case CODEC_ID_COOK:
                    for (x = 0; x < w/sps; x++)
                        get_buffer(pb, rm->audiobuf+sps*(h*x+((h+1)/2)*(y&1)+(y>>1)), sps);
                    break;
            }

            if (++(rm->sub_packet_cnt) < h)
                return -1;
            else {
                rm->sub_packet_cnt = 0;
                rm->audio_stream_num = st->index;
                rm->audio_pkt_cnt = h * w / st->codec->block_align - 1;
                // Release first audio packet
                av_new_packet(pkt, st->codec->block_align);
                memcpy(pkt->data, rm->audiobuf, st->codec->block_align);
                *timestamp = rm->audiotimestamp;
                *flags = 2; // Mark first packet as keyframe
            }
        } else if (st->codec->codec_id == CODEC_ID_AAC) {
            int x;
            rm->audio_stream_num = st->index;
            rm->sub_packet_cnt = (get_be16(pb) & 0xf0) >> 4;
            if (rm->sub_packet_cnt) {
                for (x = 0; x < rm->sub_packet_cnt; x++)
                    rm->sub_packet_lengths[x] = get_be16(pb);
                // Release first audio packet
                rm->audio_pkt_cnt = rm->sub_packet_cnt - 1;
                av_get_packet(pb, pkt, rm->sub_packet_lengths[0]);
                *flags = 2; // Mark first packet as keyframe
            }
        } else {
            av_get_packet(pb, pkt, len);
            rm_ac3_swap_bytes(st, pkt);
        }
    } else
        av_get_packet(pb, pkt, len);

    if(  (st->discard >= AVDISCARD_NONKEY && !(*flags&2))
       || st->discard >= AVDISCARD_ALL){
        av_free_packet(pkt);
        return -1;
    }

    pkt->stream_index = st->index;

#if 0
    if (st->codec->codec_type == CODEC_TYPE_VIDEO) {
        if(st->codec->codec_id == CODEC_ID_RV20){
            int seq= 128*(pkt->data[2]&0x7F) + (pkt->data[3]>>1);
            av_log(NULL, AV_LOG_DEBUG, "%d %"PRId64" %d\n", *timestamp, *timestamp*512LL/25, seq);

            seq |= (*timestamp&~0x3FFF);
            if(seq - *timestamp >  0x2000) seq -= 0x4000;
            if(seq - *timestamp < -0x2000) seq += 0x4000;
        }
    }
#endif

    pkt->pts= *timestamp;
    if (*flags & 2)
        pkt->flags |= PKT_FLAG_KEY;

    return 0;
}

void
ff_rm_retrieve_cache (AVFormatContext *s, AVStream *st, AVPacket *pkt)
{
    ByteIOContext *pb = s->pb;
    RMContext *rm = s->priv_data;

    assert (rm->audio_pkt_cnt > 0);

    if (st->codec->codec_id == CODEC_ID_AAC)
        av_get_packet(pb, pkt, rm->sub_packet_lengths[rm->sub_packet_cnt - rm->audio_pkt_cnt]);
    else {
        av_new_packet(pkt, st->codec->block_align);
        memcpy(pkt->data, rm->audiobuf + st->codec->block_align *
               (rm->sub_packet_h * rm->audio_framesize / st->codec->block_align - rm->audio_pkt_cnt),
               st->codec->block_align);
    }
    rm->audio_pkt_cnt--;
    pkt->flags = 0;
    pkt->stream_index = st->index;
}

static int rm_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    RMContext *rm = s->priv_data;
    ByteIOContext *pb = s->pb;
    AVStream *st;
    int i, len;
    int64_t timestamp, pos;
    int flags;

    if (rm->audio_pkt_cnt) {
        // If there are queued audio packet return them first
        st = s->streams[rm->audio_stream_num];
        ff_rm_retrieve_cache(s, st, pkt);
    } else if (rm->old_format) {
        st = s->streams[0];
        if (st->codec->codec_id == CODEC_ID_RA_288) {
            int x, y;

            for (y = 0; y < rm->sub_packet_h; y++)
                for (x = 0; x < rm->sub_packet_h/2; x++)
                    if (get_buffer(pb, rm->audiobuf+x*2*rm->audio_framesize+y*rm->coded_framesize, rm->coded_framesize) <= 0)
                        return AVERROR(EIO);
            rm->audio_stream_num = 0;
            rm->audio_pkt_cnt = rm->sub_packet_h * rm->audio_framesize / st->codec->block_align - 1;
            // Release first audio packet
            av_new_packet(pkt, st->codec->block_align);
            memcpy(pkt->data, rm->audiobuf, st->codec->block_align);
            pkt->flags |= PKT_FLAG_KEY; // Mark first packet as keyframe
            pkt->stream_index = 0;
        } else {
            /* just read raw bytes */
            len = RAW_PACKET_SIZE;
            len= av_get_packet(pb, pkt, len);
            pkt->stream_index = 0;
            if (len <= 0) {
                return AVERROR(EIO);
            }
            pkt->size = len;
        }
        rm_ac3_swap_bytes(st, pkt);
    } else {
        int seq=1;
resync:
        len=sync(s, &timestamp, &flags, &i, &pos);
        if(len<0)
            return AVERROR(EIO);
        st = s->streams[i];

        if (ff_rm_parse_packet (s, st, len, pkt, &seq, &flags, &timestamp) < 0)
            goto resync;

        if((flags&2) && (seq&0x7F) == 1)
            av_add_index_entry(st, pos, timestamp, 0, 0, AVINDEX_KEYFRAME);
    }

    return 0;
}

static int rm_read_close(AVFormatContext *s)
{
    RMContext *rm = s->priv_data;

    av_free(rm->audiobuf);
    av_free(rm->videobuf);
    return 0;
}

static int rm_probe(AVProbeData *p)
{
    /* check file header */
    if ((p->buf[0] == '.' && p->buf[1] == 'R' &&
         p->buf[2] == 'M' && p->buf[3] == 'F' &&
         p->buf[4] == 0 && p->buf[5] == 0) ||
        (p->buf[0] == '.' && p->buf[1] == 'r' &&
         p->buf[2] == 'a' && p->buf[3] == 0xfd))
        return AVPROBE_SCORE_MAX;
    else
        return 0;
}

static int64_t rm_read_dts(AVFormatContext *s, int stream_index,
                               int64_t *ppos, int64_t pos_limit)
{
    RMContext *rm = s->priv_data;
    int64_t pos, dts;
    int stream_index2, flags, len, h;

    pos = *ppos;

    if(rm->old_format)
        return AV_NOPTS_VALUE;

    url_fseek(s->pb, pos, SEEK_SET);
    rm->remaining_len=0;
    for(;;){
        int seq=1;
        AVStream *st;

        len=sync(s, &dts, &flags, &stream_index2, &pos);
        if(len<0)
            return AV_NOPTS_VALUE;

        st = s->streams[stream_index2];
        if (st->codec->codec_type == CODEC_TYPE_VIDEO) {
            h= get_byte(s->pb); len--;
            if(!(h & 0x40)){
                seq = get_byte(s->pb); len--;
            }
        }

        if((flags&2) && (seq&0x7F) == 1){
//            av_log(s, AV_LOG_DEBUG, "%d %d-%d %"PRId64" %d\n", flags, stream_index2, stream_index, dts, seq);
            av_add_index_entry(st, pos, dts, 0, 0, AVINDEX_KEYFRAME);
            if(stream_index2 == stream_index)
                break;
        }

        url_fskip(s->pb, len);
    }
    *ppos = pos;
    return dts;
}

AVInputFormat rm_demuxer = {
    "rm",
    NULL_IF_CONFIG_SMALL("RM format"),
    sizeof(RMContext),
    rm_probe,
    rm_read_header,
    rm_read_packet,
    rm_read_close,
    NULL,
    rm_read_dts,
};