mov.c

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.7平台上编译为嵌入式图形界面操作系统。

    MOVContext *c;
    AVStream *st;
#ifdef DEBUG
    print_atom("mdhd", atom_type, atom_offset, atom_size);
#endif

    c = (MOVContext *)param;
    st = c->fc->streams[c->fc->nb_streams-1];
    
    get_byte(pb); /* version */

    get_byte(pb); get_byte(pb);
    get_byte(pb); /* flags */

    get_be32(pb); /* creation time */
    get_be32(pb); /* modification time */

    c->streams[c->total_streams]->time_scale = get_be32(pb);

#ifdef DEBUG
    printf("track[%i].time_scale = %li\n", c->fc->nb_streams-1, c->streams[c->total_streams]->time_scale); /* time scale */
#endif
    get_be32(pb); /* duration */

    get_be16(pb); /* language */
    get_be16(pb); /* quality */
    
    return 0;
}

static int parse_hdlr(const MOVParseTableEntry *parse_table, ByteIOContext *pb, UINT32 atom_type, INT64 atom_offset, INT64 atom_size, void *param)
{
    MOVContext *c;
    int len = 0;
    char *buf;
    UINT32 type;
    AVStream *st;
    UINT32 ctype;
#ifdef DEBUG
    print_atom("hdlr", atom_type, atom_offset, atom_size);
#endif
    c = (MOVContext *)param;
    st = c->fc->streams[c->fc->nb_streams-1];

    get_byte(pb); /* version */
    get_byte(pb); get_byte(pb); get_byte(pb); /* flags */

    /* component type */
    ctype = get_le32(pb);
    type = get_le32(pb); /* component subtype */

#ifdef DEBUG
    printf("ctype= %c%c%c%c (0x%08lx)\n", *((char *)&ctype), ((char *)&ctype)[1], ((char *)&ctype)[2], ((char *)&ctype)[3], (long) ctype);
    printf("stype= %c%c%c%c\n", *((char *)&type), ((char *)&type)[1], ((char *)&type)[2], ((char *)&type)[3]);
#endif
#ifdef DEBUG
/* XXX: yeah this is ugly... */
    if(ctype == MKTAG('m', 'h', 'l', 'r')) { /* MOV */
        if(type == MKTAG('v', 'i', 'd', 'e'))
            puts("hdlr: vide");
        else if(type == MKTAG('s', 'o', 'u', 'n'))
            puts("hdlr: soun");
    } else if(ctype == 0) { /* MP4 */
        if(type == MKTAG('v', 'i', 'd', 'e'))
            puts("hdlr: vide");
        else if(type == MKTAG('s', 'o', 'u', 'n'))
            puts("hdlr: soun");
        else if(type == MKTAG('o', 'd', 's', 'm'))
            puts("hdlr: odsm");
        else if(type == MKTAG('s', 'd', 's', 'm'))
            puts("hdlr: sdsm");
    } else puts("hdlr: meta");
#endif

    if(ctype == MKTAG('m', 'h', 'l', 'r')) { /* MOV */
        /* helps parsing the string hereafter... */
        c->mp4 = 0;
        if(type == MKTAG('v', 'i', 'd', 'e'))
            st->codec.codec_type = CODEC_TYPE_VIDEO;
        else if(type == MKTAG('s', 'o', 'u', 'n'))
            st->codec.codec_type = CODEC_TYPE_AUDIO;
    } else if(ctype == 0) { /* MP4 */
        /* helps parsing the string hereafter... */
        c->mp4 = 1;
        if(type == MKTAG('v', 'i', 'd', 'e'))
            st->codec.codec_type = CODEC_TYPE_VIDEO;
        else if(type == MKTAG('s', 'o', 'u', 'n'))
            st->codec.codec_type = CODEC_TYPE_AUDIO;
    }
    get_be32(pb); /* component  manufacture */
    get_be32(pb); /* component flags */
    get_be32(pb); /* component flags mask */

    if(atom_size <= 24)
        return 0; /* nothing left to read */
    /* XXX: MP4 uses a C string, not a pascal one */
    /* component name */

    if(c->mp4) {
        /* .mp4: C string */
        while(get_byte(pb) && (++len < (atom_size - 24)));
    } else {
        /* .mov: PASCAL string */
        len = get_byte(pb);
        buf = av_malloc(len+1);
        get_buffer(pb, buf, len);
        buf[len] = '\0';
#ifdef DEBUG
        printf("**buf='%s'\n", buf);
#endif
        av_free(buf);
    }
#if 0
    len = get_byte(pb);
    /* XXX: use a better heuristic */
    if(len < 32) {
        /* assume that it is a Pascal like string */
        buf = av_malloc(len+1);
        get_buffer(pb, buf, len);
        buf[len] = '\0';
#ifdef DEBUG
        printf("**buf='%s'\n", buf);
#endif
        av_free(buf);
    } else {
        /* MP4 string */
        for(;;) {
            if (len == 0)
                break;
            len = get_byte(pb);
        }
    }
#endif
    
    return 0;
}

static int mp4_read_descr_len(ByteIOContext *pb)
{
    int c, len, count;

    len = 0;
    count = 0;
    for(;;) {
        c = get_byte(pb);
        len = (len << 7) | (c & 0x7f);
        if ((c & 0x80) == 0)
            break;
        if (++count == 4)
            break;
    }
    return len;
}

static int mp4_read_descr(ByteIOContext *pb, int *tag)
{
    int len;
    *tag = get_byte(pb);
    len = mp4_read_descr_len(pb);
#ifdef DEBUG
    printf("MPEG4 description: tag=0x%02x len=%d\n", *tag, len);
#endif
    return len;
}

static int parse_stsd(const MOVParseTableEntry *parse_table, ByteIOContext *pb, UINT32 atom_type, INT64 atom_offset, INT64 atom_size, void *param)
{
    MOVContext *c;
    int entries, size, samp_sz, frames_per_sample, id;
    UINT32 format;
    AVStream *st;
    MOVStreamContext *sc;
#ifdef DEBUG
    print_atom("stsd", atom_type, atom_offset, atom_size);
#endif
    c = (MOVContext *)param;
    st = c->fc->streams[c->fc->nb_streams-1];
    sc = (MOVStreamContext *)st->priv_data;

    get_byte(pb); /* version */
    get_byte(pb); get_byte(pb); get_byte(pb); /* flags */

    entries = get_be32(pb);

    while(entries--) {
        size = get_be32(pb); /* size */
        format = get_le32(pb); /* data format */
        
        get_be32(pb); /* reserved */
        get_be16(pb); /* reserved */
        get_be16(pb); /* index */

        /* for MPEG4: set codec type by looking for it */
        id = codec_get_id(mov_video_tags, format);
        if (id >= 0) {
            AVCodec *codec;
            codec = avcodec_find_decoder(id);
            if (codec)
                st->codec.codec_type = codec->type;
        }
#ifdef DEBUG
        printf("size=%d 4CC= %c%c%c%c codec_type=%d\n", 
               size, 
               (format >> 0) & 0xff,
               (format >> 8) & 0xff,
               (format >> 16) & 0xff,
               (format >> 24) & 0xff,
               st->codec.codec_type);
#endif
        if(st->codec.codec_type==CODEC_TYPE_VIDEO) {
            st->codec.codec_tag = format;
            st->codec.codec_id = codec_get_id(mov_video_tags, format);
            get_be16(pb); /* version */
            get_be16(pb); /* revision level */
            get_be32(pb); /* vendor */
            get_be32(pb); /* temporal quality */
            get_be32(pb); /* spacial quality */
            st->codec.width = get_be16(pb); /* width */
            st->codec.height = get_be16(pb); /* height */
#if 1
            if (st->codec.codec_id == CODEC_ID_MPEG4) {
                /* in some MPEG4 the width/height are not correct, so
                   we ignore this info */
                st->codec.width = 0;
                st->codec.height = 0;
            }
#endif
            get_be32(pb); /* horiz resolution */
            get_be32(pb); /* vert resolution */
            get_be32(pb); /* data size, always 0 */
            frames_per_sample = get_be16(pb); /* frame per samples */
#ifdef DEBUG
	    printf("frames/samples = %d\n", frames_per_sample);
#endif
            url_fskip(pb, 32); /* codec name */

            get_be16(pb); /* depth */
            get_be16(pb); /* colortable id */
            
            st->codec.frame_rate = 25 * FRAME_RATE_BASE;
            
            size -= (16+8*4+2+32+2*2);
            while (size >= 8) {
                int atom_size, atom_type;
                INT64 start_pos;
                
                atom_size = get_be32(pb);
                atom_type = get_le32(pb);
                size -= 8;
#ifdef DEBUG
                printf("VIDEO: atom_type=%c%c%c%c atom_size=%d size_left=%d\n", 
                       (atom_type >> 0) & 0xff,
                       (atom_type >> 8) & 0xff,
                       (atom_type >> 16) & 0xff,
                       (atom_type >> 24) & 0xff,
                       atom_size, size);
#endif
                start_pos = url_ftell(pb);

                switch(atom_type) {
                case MKTAG('e', 's', 'd', 's'):
                    {
                        int tag, len;
                        /* Well, broken but suffisant for some MP4 streams */
                        get_be32(pb); /* version + flags */
                        len = mp4_read_descr(pb, &tag);
                        if (tag == 0x03) {
                            /* MP4ESDescrTag */
                            get_be16(pb); /* ID */
                            get_byte(pb); /* priority */
                            len = mp4_read_descr(pb, &tag);
                            if (tag != 0x04)
                                goto fail;
                            /* MP4DecConfigDescrTag */
                            get_byte(pb); /* objectTypeId */
                            get_be32(pb); /* streamType + buffer size */
                            get_be32(pb); /* max bit rate */
                            get_be32(pb); /* avg bit rate */
                            len = mp4_read_descr(pb, &tag);
                            if (tag != 0x05)
                                goto fail;
                            /* MP4DecSpecificDescrTag */
#ifdef DEBUG
                            printf("Specific MPEG4 header len=%d\n", len);
#endif
                            sc->header_data = av_mallocz(len);
                            if (sc->header_data) {
                                get_buffer(pb, sc->header_data, len);
                                sc->header_len = len;
                            }
                        }
                        /* in any case, skip garbage */
                    }
                    break;
                default:
                    break;
                }
            fail:
                url_fskip(pb, (atom_size - 8) - 
                          ((url_ftell(pb) - start_pos)));
                size -= atom_size - 8;
            }
            if (size > 0) {
                /* unknown extension */
                url_fskip(pb, size);
            }
        } else {
            st->codec.codec_tag = format;

            get_be16(pb); /* version */
            get_be16(pb); /* revision level */
            get_be32(pb); /* vendor */

            st->codec.channels = get_be16(pb);/* channel count */
            samp_sz = get_be16(pb); /* sample size */
#ifdef DEBUG
            if(samp_sz != 16)
                puts("!!! stsd: audio sample size is not 16 bit !");
#endif            
            st->codec.codec_id = codec_get_id(mov_audio_tags, format);
            /* handle specific s8 codec */
            if (st->codec.codec_id == CODEC_ID_PCM_S16BE && samp_sz == 8)
            st->codec.codec_id = CODEC_ID_PCM_S8;

            get_be16(pb); /* compression id = 0*/
            get_be16(pb); /* packet size = 0 */
            
            st->codec.sample_rate = ((get_be32(pb) >> 16));
            st->codec.bit_rate = 0;
#if 0

            get_be16(pb); get_be16(pb); /*  */
            get_be16(pb); /*  */
            get_be16(pb); /*  */
            get_be16(pb); /*  */
            get_be16(pb); /*  */
#endif            
            if(size > 16)
                url_fskip(pb, size-(16+20));
        }
    }
/*
    if(len) {
    buf = av_malloc(len+1);
        get_buffer(pb, buf, len);
        buf[len] = '\0';
        puts(buf);
        av_free(buf);
    }
*/
    return 0;
}

static int parse_stco(const MOVParseTableEntry *parse_table, ByteIOContext *pb, UINT32 atom_type, INT64 atom_offset, INT64 atom_size, void *param)
{
    MOVContext *c;
    int entries, i;
    AVStream *st;
    MOVStreamContext *sc;
#ifdef DEBUG
    print_atom("stco", atom_type, atom_offset, atom_size);
#endif
    c = (MOVContext *)param;
    st = c->fc->streams[c->fc->nb_streams-1];
    sc = (MOVStreamContext *)st->priv_data;
    
    get_byte(pb); /* version */
    get_byte(pb); get_byte(pb); get_byte(pb); /* flags */

    entries = get_be32(pb);
    sc->chunk_count = entries;
    sc->chunk_offsets = av_malloc(entries * sizeof(INT64));
    if(atom_type == MKTAG('s', 't', 'c', 'o')) {
        for(i=0; i<entries; i++) {
            sc->chunk_offsets[i] = get_be32(pb);
        }
    } else if(atom_type == MKTAG('c', 'o', '6', '4')) {
        for(i=0; i<entries; i++) {
            sc->chunk_offsets[i] = get_be64(pb);
        }
    } else
        return -1;
#ifdef DEBUG
/*
    for(i=0; i<entries; i++) {
        printf("chunk offset=0x%Lx\n", sc->chunk_offsets[i]);
    }
*/
#endif
    return 0;
}

static int parse_stsc(const MOVParseTableEntry *parse_table, ByteIOContext *pb, UINT32 atom_type, INT64 atom_offset, INT64 atom_size, void *param)
{
    MOVContext *c;
    int entries, i;
    AVStream *st;
    MOVStreamContext *sc;
#ifdef DEBUG
    print_atom("stsc", atom_type, atom_offset, atom_size);
#endif
    c = (MOVContext *)param;
    st = c->fc->streams[c->fc->nb_streams-1];
    sc = (MOVStreamContext *)st->priv_data;
    
    get_byte(pb); /* version */
    get_byte(pb); get_byte(pb); get_byte(pb); /* flags */

    entries = get_be32(pb);
#ifdef DEBUG
printf("track[%i].stsc.entries = %i\n", c->fc->nb_streams-1, entries);
#endif
    sc->sample_to_chunk_sz = entries;
    sc->sample_to_chunk = av_malloc(entries * sizeof(MOV_sample_to_chunk_tbl));
    for(i=0; i<entries; i++) {
        sc->sample_to_chunk[i].first = get_be32(pb);
        sc->sample_to_chunk[i].count = get_be32(pb);
        sc->sample_to_chunk[i].id = get_be32(pb);
#ifdef DEBUG
/*        printf("sample_to_chunk first=%ld count=%ld, id=%ld\n", sc->sample_to_chunk[i].first, sc->sample_to_chunk[i].count, sc->sample_to_chunk[i].id); */
#endif
    }
    return 0;
}

static int parse_stsz(const MOVParseTableEntry *parse_table, ByteIOContext *pb, UINT32 atom_type, INT64 atom_offset, INT64 atom_size, void *param)
{
    MOVContext *c;
    int entries, i;
    AVStream *st;
    MOVStreamContext *sc;
#ifdef DEBUG
    print_atom("stsz", atom_type, atom_offset, atom_size);
#endif
    c = (MOVContext *)param;
    st = c->fc->streams[c->fc->nb_streams-1];
    sc = (MOVStreamContext *)st->priv_data;
    
    get_byte(pb); /* version */
    get_byte(pb); get_byte(pb); get_byte(pb); /* flags */
    
    sc->sample_size = get_be32(pb);
    entries = get_be32(pb);
    sc->sample_count = entries;
#ifdef DEBUG
    printf("sample_size = %ld sample_count = %ld\n", sc->sample_size, sc->sample_count);
#endif
    if(sc->sample_size)
        return 0; /* there isn't any table following */
    sc->sample_sizes = av_malloc(entries * sizeof(long));