mov.c

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.10平台上编译为嵌入式图形界面操作系统。

        /* 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 */
#ifdef DEBUG
        char* buf;
#endif
        len = get_byte(pb);
#ifdef DEBUG
	buf = (uint8_t*) av_malloc(len+1);
	if (buf) {
	    get_buffer(pb, buf, len);
	    buf[len] = '\0';
	    printf("**buf='%s'\n", buf);
	    av_free(buf);
	} else
#endif
	    url_fskip(pb, len);
    }

    return 0;
}

static int mov_mp4_read_descr_len(ByteIOContext *pb)
{
    int len = 0;
    int count = 4;
    while (count--) {
        int c = get_byte(pb);
	len = (len << 7) | (c & 0x7f);
	if (!(c & 0x80))
	    break;
    }
    return len;
}

static int mov_mp4_read_descr(ByteIOContext *pb, int *tag)
{
    int len;
    *tag = get_byte(pb);
    len = mov_mp4_read_descr_len(pb);
#ifdef DEBUG
    printf("MPEG4 description: tag=0x%02x len=%d\n", *tag, len);
#endif
    return len;
}

static inline unsigned int get_be24(ByteIOContext *s)
{
    unsigned int val;
    val = get_byte(s) << 16;
    val |= get_byte(s) << 8;
    val |= get_byte(s);
    return val;
}

static int mov_read_esds(MOVContext *c, ByteIOContext *pb, MOV_atom_t atom)
{
    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
    MOVStreamContext *sc = (MOVStreamContext *)st->priv_data;
    int64_t start_pos = url_ftell(pb);
    int tag, len;

    print_atom("esds", atom);

    /* Well, broken but suffisant for some MP4 streams */
    get_be32(pb); /* version + flags */
    len = mov_mp4_read_descr(pb, &tag);
    if (tag == MP4ESDescrTag) {
	get_be16(pb); /* ID */
	get_byte(pb); /* priority */
    } else
	get_be16(pb); /* ID */

    len = mov_mp4_read_descr(pb, &tag);
    if (tag == MP4DecConfigDescrTag) {
	sc->esds.object_type_id = get_byte(pb);
	sc->esds.stream_type = get_byte(pb);
	sc->esds.buffer_size_db = get_be24(pb);
	sc->esds.max_bitrate = get_be32(pb);
	sc->esds.avg_bitrate = get_be32(pb);

	len = mov_mp4_read_descr(pb, &tag);
	//printf("LEN %d  TAG %d  m:%d a:%d\n", len, tag, sc->esds.max_bitrate, sc->esds.avg_bitrate);
	if (tag == MP4DecSpecificDescrTag) {
#ifdef DEBUG
	    printf("Specific MPEG4 header len=%d\n", len);
#endif
	    st->codec.extradata = (uint8_t*) av_mallocz(len);
	    if (st->codec.extradata) {
		get_buffer(pb, st->codec.extradata, len);
		st->codec.extradata_size = len;
	    }
	}
    }
    /* in any case, skip garbage */
    url_fskip(pb, atom.size - ((url_ftell(pb) - start_pos)));
    return 0;
}

/* this atom contains actual media data */
static int mov_read_mdat(MOVContext *c, ByteIOContext *pb, MOV_atom_t atom)
{
    print_atom("mdat", atom);

    if(atom.size == 0) /* wrong one (MP4) */
        return 0;
    c->found_mdat=1;
    c->mdat_offset = atom.offset;
    c->mdat_size = atom.size;
    if(c->found_moov)
        return 1; /* found both, just go */
    url_fskip(pb, atom.size);
    return 0; /* now go for moov */
}

/* this atom should contain all header atoms */
static int mov_read_moov(MOVContext *c, ByteIOContext *pb, MOV_atom_t atom)
{
    int err;

    print_atom("moov", atom);

    err = mov_read_default(c, pb, atom);
    /* we parsed the 'moov' atom, we can terminate the parsing as soon as we find the 'mdat' */
    /* so we don't parse the whole file if over a network */
    c->found_moov=1;
    if(c->found_mdat)
        return 1; /* found both, just go */
    return 0; /* now go for mdat */
}


static int mov_read_mdhd(MOVContext *c, ByteIOContext *pb, MOV_atom_t atom)
{
    print_atom("mdhd", atom);

    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 = %i\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 mov_read_mvhd(MOVContext *c, ByteIOContext *pb, MOV_atom_t atom)
{
    print_atom("mvhd", atom);

    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->time_scale = get_be32(pb); /* time scale */
#ifdef DEBUG
    printf("time scale = %i\n", c->time_scale);
#endif
    c->duration = get_be32(pb); /* duration */
    get_be32(pb); /* preferred scale */

    get_be16(pb); /* preferred volume */

    url_fskip(pb, 10); /* reserved */

    url_fskip(pb, 36); /* display matrix */

    get_be32(pb); /* preview time */
    get_be32(pb); /* preview duration */
    get_be32(pb); /* poster time */
    get_be32(pb); /* selection time */
    get_be32(pb); /* selection duration */
    get_be32(pb); /* current time */
    get_be32(pb); /* next track ID */

    return 0;
}

static int mov_read_smi(MOVContext *c, ByteIOContext *pb, MOV_atom_t atom)
{
    AVStream *st = c->fc->streams[c->fc->nb_streams-1];

    // currently SVQ3 decoder expect full STSD header - so let's fake it
    // this should be fixed and just SMI header should be passed
    av_free(st->codec.extradata);
    st->codec.extradata_size = 0x5a + atom.size;
    st->codec.extradata = (uint8_t*) av_mallocz(st->codec.extradata_size);

    if (st->codec.extradata) {
	strcpy(st->codec.extradata, "SVQ3"); // fake
	get_buffer(pb, st->codec.extradata + 0x5a, atom.size);
	//printf("Reading SMI %Ld  %s\n", atom.size, (char*)st->codec.extradata + 0x5a);
    } else
	url_fskip(pb, atom.size);

    return 0;
}

static int mov_read_stco(MOVContext *c, ByteIOContext *pb, MOV_atom_t atom)
{
    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
    MOVStreamContext *sc = (MOVStreamContext *)st->priv_data;
    int entries, i;

    print_atom("stco", atom);

    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 = (int64_t*) av_malloc(entries * sizeof(int64_t));
    if (!sc->chunk_offsets)
        return -1;
    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 mov_read_stsd(MOVContext *c, ByteIOContext *pb, MOV_atom_t atom)
{
    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
    //MOVStreamContext *sc = (MOVStreamContext *)st->priv_data;
    int entries, frames_per_sample;
    uint32_t format;

    /* for palette traversal */
    int color_depth;
    int color_start;
    int color_count;
    int color_end;
    int color_index;
    int color_dec;
    int color_greyscale;
    unsigned char *color_table;
    int j;
    unsigned char r, g, b;

    print_atom("stsd", atom);

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

    entries = get_be32(pb);

    while(entries--) { //Parsing Sample description table
        enum CodecID id;
	int 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
	st->codec.codec_tag = format;
	if(st->codec.codec_type==CODEC_TYPE_VIDEO) {
	    MOV_atom_t a = { 0, 0, 0 };
            st->codec.codec_id = id;
            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); /* frames per samples */
#ifdef DEBUG
	    printf("frames/samples = %d\n", frames_per_sample);
#endif
	    get_buffer(pb, (uint8_t *)st->codec.codec_name, 32); /* codec name */

	    st->codec.bits_per_sample = get_be16(pb); /* depth */
            st->codec.color_table_id = get_be16(pb); /* colortable id */

/*          These are set in mov_read_stts and might already be set!
            st->codec.frame_rate      = 25;
            st->codec.frame_rate_base = 1;
*/
	    size -= (16+8*4+2+32+2*2);
#if 0
	    while (size >= 8) {
		MOV_atom_t a;
                int64_t start_pos;

		a.size = get_be32(pb);
		a.type = get_le32(pb);
		size -= 8;
#ifdef DEBUG
                printf("VIDEO: atom_type=%c%c%c%c atom.size=%Ld size_left=%d\n",
                       (a.type >> 0) & 0xff,
                       (a.type >> 8) & 0xff,
                       (a.type >> 16) & 0xff,
                       (a.type >> 24) & 0xff,
		       a.size, size);
#endif
                start_pos = url_ftell(pb);

		switch(a.type) {
                case MKTAG('e', 's', 'd', 's'):
                    {
                        int tag, len;
                        /* Well, broken but suffisant for some MP4 streams */
                        get_be32(pb); /* version + flags */
			len = mov_mp4_read_descr(pb, &tag);
                        if (tag == 0x03) {
                            /* MP4ESDescrTag */
                            get_be16(pb); /* ID */
                            get_byte(pb); /* priority */
			    len = mov_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 = mov_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:
		printf("ATOMENEWSIZE %Ld   %d\n", atom.size, url_ftell(pb) - start_pos);
		if (atom.size > 8) {
		    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

            /* figure out the palette situation */
            color_depth = st->codec.bits_per_sample & 0x1F;
            color_greyscale = st->codec.bits_per_sample & 0x20;

            /* if the depth is 2, 4, or 8 bpp, file is palettized */
            if ((color_depth == 2) || (color_depth == 4) || 
                (color_depth == 8)) {

                if (color_greyscale) {

                    /* compute the greyscale palette */
                    color_count = 1 << color_depth;
                    color_index = 255;