C++ MKTAG函数代码示例

static int read_header(AVFormatContext *s)
{
    BRSTMDemuxContext *b = s->priv_data;
    int bom, major, minor, codec, chunk;
    int64_t pos, h1offset, toffset;
    uint32_t size, start, asize;
    AVStream *st;
    int ret = AVERROR_EOF;

    st = avformat_new_stream(s, NULL);
    if (!st)
        return AVERROR(ENOMEM);
    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

    avio_skip(s->pb, 4);

    bom = avio_rb16(s->pb);
    if (bom != 0xFEFF && bom != 0xFFFE) {
        av_log(s, AV_LOG_ERROR, "invalid byte order: %X\n", bom);
        return AVERROR_INVALIDDATA;
    }
    if (bom == 0xFFFE) {
        avpriv_request_sample(s, "little endian byte order");
        return AVERROR_PATCHWELCOME;
    }

    major = avio_r8(s->pb);
    minor = avio_r8(s->pb);
    avio_skip(s->pb, 4); // size of file
    size = avio_rb16(s->pb);
    if (size < 14)
        return AVERROR_INVALIDDATA;

    avio_skip(s->pb, size - 14);
    pos = avio_tell(s->pb);
    if (avio_rl32(s->pb) != MKTAG('H','E','A','D'))
        return AVERROR_INVALIDDATA;
    size = avio_rb32(s->pb);
    if (size < 256)
        return AVERROR_INVALIDDATA;
    avio_skip(s->pb, 4); // unknown
    h1offset = avio_rb32(s->pb);
    if (h1offset > size)
        return AVERROR_INVALIDDATA;
    avio_skip(s->pb, 12);
    toffset = avio_rb32(s->pb) + 16LL;
    if (toffset > size)
        return AVERROR_INVALIDDATA;

    avio_skip(s->pb, pos + h1offset + 8 - avio_tell(s->pb));
    codec = avio_r8(s->pb);

    switch (codec) {
    case 0: codec = AV_CODEC_ID_PCM_S8_PLANAR;    break;
    case 1: codec = AV_CODEC_ID_PCM_S16BE_PLANAR; break;
    case 2: codec = AV_CODEC_ID_ADPCM_THP;        break;
    default:
        avpriv_request_sample(s, "codec %d", codec);
        return AVERROR_PATCHWELCOME;
    }

    avio_skip(s->pb, 1); // loop flag
    st->codec->codec_id = codec;
    st->codec->channels = avio_r8(s->pb);
    if (!st->codec->channels)
        return AVERROR_INVALIDDATA;

    avio_skip(s->pb, 1); // padding
    st->codec->sample_rate = avio_rb16(s->pb);
    if (!st->codec->sample_rate)
        return AVERROR_INVALIDDATA;

    avio_skip(s->pb, 2); // padding
    avio_skip(s->pb, 4); // loop start sample
    st->start_time = 0;
    st->duration = avio_rb32(s->pb);
    avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);

    start = avio_rb32(s->pb);
    b->current_block = 0;
    b->block_count = avio_rb32(s->pb);
    if (b->block_count > UINT16_MAX) {
        av_log(s, AV_LOG_WARNING, "too many blocks: %u\n", b->block_count);
        return AVERROR_INVALIDDATA;
    }

    b->block_size = avio_rb32(s->pb);
    if (b->block_size > UINT16_MAX / st->codec->channels)
        return AVERROR_INVALIDDATA;
    b->block_size *= st->codec->channels;

    b->samples_per_block = avio_rb32(s->pb);
    b->last_block_used_bytes = avio_rb32(s->pb);
    if (b->last_block_used_bytes > UINT16_MAX / st->codec->channels)
        return AVERROR_INVALIDDATA;
    b->last_block_used_bytes *= st->codec->channels;

    avio_skip(s->pb, 4); // last block samples
    avio_skip(s->pb, 4); // last block size

//.........这里部分代码省略.........

bool AVIDecoder::AVIVideoTrack::isTruemotion1() const {
	return _bmInfo.compression == MKTAG('D', 'U', 'C', 'K') || _bmInfo.compression == MKTAG('d', 'u', 'c', 'k');
}

static int img_write_packet(AVFormatContext *s, AVPacket *pkt)
{
    VideoData *img = s->priv_data;
    ByteIOContext *pb[3];
    char filename[1024];
    AVCodecContext *codec= s->streams[ pkt->stream_index ]->codec;
    int i;

    if (!img->is_pipe) {
        if (av_get_frame_filename(filename, sizeof(filename),
                                  img->path, img->img_number) < 0 && img->img_number>1) {
            av_log(s, AV_LOG_ERROR, "Could not get frame filename from pattern\n");
            return AVERROR(EIO);
        }
        for(i=0; i<3; i++){
            if (url_fopen(&pb[i], filename, URL_WRONLY) < 0) {
                av_log(s, AV_LOG_ERROR, "Could not open file : %s\n",filename);
                return AVERROR(EIO);
            }

            if(codec->codec_id != CODEC_ID_RAWVIDEO)
                break;
            filename[ strlen(filename) - 1 ]= 'U' + i;
        }
    } else {
        pb[0] = s->pb;
    }

    if(codec->codec_id == CODEC_ID_RAWVIDEO){
        int ysize = codec->width * codec->height;
        put_buffer(pb[0], pkt->data        , ysize);
        put_buffer(pb[1], pkt->data + ysize, (pkt->size - ysize)/2);
        put_buffer(pb[2], pkt->data + ysize +(pkt->size - ysize)/2, (pkt->size - ysize)/2);
        put_flush_packet(pb[1]);
        put_flush_packet(pb[2]);
        url_fclose(pb[1]);
        url_fclose(pb[2]);
    }else{
        if(av_str2id(img_tags, s->filename) == CODEC_ID_JPEG2000){
            AVStream *st = s->streams[0];
            if(st->codec->extradata_size > 8 &&
               AV_RL32(st->codec->extradata+4) == MKTAG('j','p','2','h')){
                if(pkt->size < 8 || AV_RL32(pkt->data+4) != MKTAG('j','p','2','c'))
                    goto error;
                put_be32(pb[0], 12);
                put_tag (pb[0], "jP  ");
                put_be32(pb[0], 0x0D0A870A); // signature
                put_be32(pb[0], 20);
                put_tag (pb[0], "ftyp");
                put_tag (pb[0], "jp2 ");
                put_be32(pb[0], 0);
                put_tag (pb[0], "jp2 ");
                put_buffer(pb[0], st->codec->extradata, st->codec->extradata_size);
            }else if(pkt->size < 8 ||
                     (!st->codec->extradata_size &&
                      AV_RL32(pkt->data+4) != MKTAG('j','P',' ',' '))){ // signature
            error:
                av_log(s, AV_LOG_ERROR, "malformated jpeg2000 codestream\n");
                return -1;
            }
        }
        put_buffer(pb[0], pkt->data, pkt->size);
    }
    put_flush_packet(pb[0]);
    if (!img->is_pipe) {
        url_fclose(pb[0]);
    }

    img->img_number++;
    return 0;
}

/* mmf input */
static int mmf_read_header(AVFormatContext *s,
                           AVFormatParameters *ap)
{
    MMFContext *mmf = s->priv_data;
    unsigned int tag;
    ByteIOContext *pb = &s->pb;
    AVStream *st;
    offset_t file_size, size;
    int rate, params;

    tag = get_le32(pb);
    if (tag != MKTAG('M', 'M', 'M', 'D'))
        return -1;
    file_size = get_be32(pb);

    /* Skip some unused chunks that may or may not be present */
    for(;; url_fseek(pb, size, SEEK_CUR)) {
        tag = get_le32(pb);
        size = get_be32(pb);
        if(tag == MKTAG('C','N','T','I')) continue;
        if(tag == MKTAG('O','P','D','A')) continue;
        break;
    }

    /* Tag = "ATRx", where "x" = track number */
    if ((tag & 0xffffff) == MKTAG('M', 'T', 'R', 0)) {
        av_log(s, AV_LOG_ERROR, "MIDI like format found, unsupported\n");
        return -1;
    }
    if ((tag & 0xffffff) != MKTAG('A', 'T', 'R', 0)) {
        av_log(s, AV_LOG_ERROR, "Unsupported SMAF chunk %08x\n", tag);
        return -1;
    }

    get_byte(pb); /* format type */
    get_byte(pb); /* sequence type */
    params = get_byte(pb); /* (channel << 7) | (format << 4) | rate */
    rate = mmf_rate(params & 0x0f);
    if(rate  < 0) {
        av_log(s, AV_LOG_ERROR, "Invalid sample rate\n");
        return -1;
    }
    get_byte(pb); /* wave base bit */
    get_byte(pb); /* time base d */
    get_byte(pb); /* time base g */

    /* Skip some unused chunks that may or may not be present */
    for(;; url_fseek(pb, size, SEEK_CUR)) {
        tag = get_le32(pb);
        size = get_be32(pb);
        if(tag == MKTAG('A','t','s','q')) continue;
        if(tag == MKTAG('A','s','p','I')) continue;
        break;
    }

    /* Make sure it's followed by an Awa chunk, aka wave data */
    if ((tag & 0xffffff) != MKTAG('A', 'w', 'a', 0)) {
        av_log(s, AV_LOG_ERROR, "Unexpected SMAF chunk %08x\n", tag);
        return -1;
    }
    mmf->data_size = size;

    st = av_new_stream(s, 0);
    if (!st)
        return AVERROR_NOMEM;

    st->codec->codec_type = CODEC_TYPE_AUDIO;
    st->codec->codec_id = CODEC_ID_ADPCM_YAMAHA;
    st->codec->sample_rate = rate;
    st->codec->channels = 1;
    st->codec->bits_per_sample = 4;
    st->codec->bit_rate = st->codec->sample_rate * st->codec->bits_per_sample;

    av_set_pts_info(st, 64, 1, st->codec->sample_rate);

    return 0;
}

static int wv_read_block_header(AVFormatContext *ctx, ByteIOContext *pb)
{
    WVContext *wc = ctx->priv_data;
    uint32_t tag, ver;
    int size;
    int rate, bpp, chan;

    wc->pos = url_ftell(pb);
    tag = get_le32(pb);
    if (tag != MKTAG('w', 'v', 'p', 'k'))
        return -1;
    size = get_le32(pb);
    if(size < 24 || size > WV_BLOCK_LIMIT){
        av_log(ctx, AV_LOG_ERROR, "Incorrect block size %i\n", size);
        return -1;
    }
    wc->blksize = size;
    ver = get_le16(pb);
    if(ver < 0x402 || ver > 0x410){
        av_log(ctx, AV_LOG_ERROR, "Unsupported version %03X\n", ver);
        return -1;
    }
    get_byte(pb); // track no
    get_byte(pb); // track sub index
    wc->samples = get_le32(pb); // total samples in file
    wc->soff = get_le32(pb); // offset in samples of current block
    get_buffer(pb, wc->extra, WV_EXTRA_SIZE);
    wc->flags = AV_RL32(wc->extra + 4);
    //parse flags
    bpp = ((wc->flags & 3) + 1) << 3;
    chan = 1 + !(wc->flags & WV_MONO);
    rate = wv_rates[(wc->flags >> 23) & 0xF];
    if(rate == -1 && !wc->block_parsed){
        int64_t block_end = url_ftell(pb) + wc->blksize - 24;
        if(url_is_streamed(pb)){
            av_log(ctx, AV_LOG_ERROR, "Cannot determine custom sampling rate\n");
            return -1;
        }
        while(url_ftell(pb) < block_end){
            int id, size;
            id = get_byte(pb);
            size = (id & 0x80) ? get_le24(pb) : get_byte(pb);
            size <<= 1;
            if(id&0x40)
                size--;
            if((id&0x3F) == 0x27){
                rate = get_le24(pb);
                break;
            }else{
                url_fskip(pb, size);
            }
        }
        if(rate == -1){
            av_log(ctx, AV_LOG_ERROR, "Cannot determine custom sampling rate\n");
            return -1;
        }
        url_fseek(pb, block_end - wc->blksize + 24, SEEK_SET);
    }
    if(!wc->bpp) wc->bpp = bpp;
    if(!wc->chan) wc->chan = chan;
    if(!wc->rate) wc->rate = rate;

    if(wc->flags && bpp != wc->bpp){
        av_log(ctx, AV_LOG_ERROR, "Bits per sample differ, this block: %i, header block: %i\n", bpp, wc->bpp);
        return -1;
    }
    if(wc->flags && chan != wc->chan){
        av_log(ctx, AV_LOG_ERROR, "Channels differ, this block: %i, header block: %i\n", chan, wc->chan);
        return -1;
    }
    if(wc->flags && rate != -1 && rate != wc->rate){
        av_log(ctx, AV_LOG_ERROR, "Sampling rate differ, this block: %i, header block: %i\n", rate, wc->rate);
        return -1;
    }
    wc->blksize = size - 24;
    return 0;
}

static int ffm_write_header(AVFormatContext *s)
{
    FFMContext *ffm = s->priv_data;
    AVDictionaryEntry *t;
    AVStream *st;
    AVIOContext *pb = s->pb;
    AVCodecContext *codec;
    int bit_rate, i, ret;

    if (t = av_dict_get(s->metadata, "creation_time", NULL, 0)) {
        ret = av_parse_time(&ffm->start_time, t->value, 0);
        if (ret < 0)
            return ret;
    }

    ffm->packet_size = FFM_PACKET_SIZE;

    /* header */
    avio_wl32(pb, MKTAG('F', 'F', 'M', '2'));
    avio_wb32(pb, ffm->packet_size);
    avio_wb64(pb, 0); /* current write position */

    if(avio_open_dyn_buf(&pb) < 0)
        return AVERROR(ENOMEM);

    avio_wb32(pb, s->nb_streams);
    bit_rate = 0;
    for(i=0;i<s->nb_streams;i++) {
        st = s->streams[i];
        bit_rate += st->codec->bit_rate;
    }
    avio_wb32(pb, bit_rate);

    write_header_chunk(s->pb, pb, MKBETAG('M', 'A', 'I', 'N'));

    /* list of streams */
    for(i=0;i<s->nb_streams;i++) {
        st = s->streams[i];
        avpriv_set_pts_info(st, 64, 1, 1000000);
        if(avio_open_dyn_buf(&pb) < 0)
            return AVERROR(ENOMEM);

        codec = st->codec;
        /* generic info */
        avio_wb32(pb, codec->codec_id);
        avio_w8(pb, codec->codec_type);
        avio_wb32(pb, codec->bit_rate);
        avio_wb32(pb, codec->flags);
        avio_wb32(pb, codec->flags2);
        avio_wb32(pb, codec->debug);
        if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
            avio_wb32(pb, codec->extradata_size);
            avio_write(pb, codec->extradata, codec->extradata_size);
        }
        write_header_chunk(s->pb, pb, MKBETAG('C', 'O', 'M', 'M'));
        /* specific info */
        switch(codec->codec_type) {
        case AVMEDIA_TYPE_VIDEO:
            if (st->recommended_encoder_configuration) {
                av_log(NULL, AV_LOG_DEBUG, "writing recommended configuration: %s\n",
                       st->recommended_encoder_configuration);
                if ((ret = ffm_write_recommended_config(s->pb, codec, MKBETAG('S', '2', 'V', 'I'),
                                                        st->recommended_encoder_configuration)) < 0)
                return ret;
            } else if ((ret = ffm_write_header_codec_ctx(s->pb, codec, MKBETAG('S', '2', 'V', 'I'), AV_OPT_FLAG_VIDEO_PARAM)) < 0 ||
                       (ret = ffm_write_header_codec_private_ctx(s, codec, AV_OPT_FLAG_VIDEO_PARAM)) < 0)
                return ret;
            break;
        case AVMEDIA_TYPE_AUDIO:
            if (st->recommended_encoder_configuration) {
                av_log(NULL, AV_LOG_DEBUG, "writing recommended configuration: %s\n",
                       st->recommended_encoder_configuration);
                if ((ret = ffm_write_recommended_config(s->pb, codec, MKBETAG('S', '2', 'A', 'U'),
                                                        st->recommended_encoder_configuration)) < 0)
                return ret;
            } else if ((ret = ffm_write_header_codec_ctx(s->pb, codec, MKBETAG('S', '2', 'A', 'U'), AV_OPT_FLAG_AUDIO_PARAM)) < 0 ||
                     (ret = ffm_write_header_codec_private_ctx(s, codec, AV_OPT_FLAG_AUDIO_PARAM)) < 0)
                return ret;
            break;
        default:
            return -1;
        }
    }
    pb = s->pb;

    avio_wb64(pb, 0); // end of header

    /* flush until end of block reached */
    while ((avio_tell(pb) % ffm->packet_size) != 0)
        avio_w8(pb, 0);

    avio_flush(pb);

    /* init packet mux */
    ffm->packet_ptr = ffm->packet;
    ffm->packet_end = ffm->packet + ffm->packet_size - FFM_HEADER_SIZE;
    av_assert0(ffm->packet_end >= ffm->packet);
    ffm->frame_offset = 0;
    ffm->dts = 0;
    ffm->first_packet = 1;
//.........这里部分代码省略.........

static int read_header(AVFormatContext *s)
{
    BRSTMDemuxContext *b = s->priv_data;
    int bom, major, minor, codec, chunk;
    int64_t h1offset, pos, toffset;
    uint32_t size, asize, start = 0;
    AVStream *st;
    int ret = AVERROR_EOF;
    int bfstm = !strcmp("bfstm", s->iformat->name);

    st = avformat_new_stream(s, NULL);
    if (!st)
        return AVERROR(ENOMEM);
    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

    avio_skip(s->pb, 4);

    bom = avio_rb16(s->pb);
    if (bom != 0xFEFF && bom != 0xFFFE) {
        av_log(s, AV_LOG_ERROR, "invalid byte order: %X\n", bom);
        return AVERROR_INVALIDDATA;
    }

    if (bom == 0xFFFE)
        b->little_endian = 1;

    if (!bfstm) {
        major = avio_r8(s->pb);
        minor = avio_r8(s->pb);
        avio_skip(s->pb, 4); // size of file
        size = read16(s);
        if (size < 14)
            return AVERROR_INVALIDDATA;

        avio_skip(s->pb, size - 14);
        pos = avio_tell(s->pb);
        if (avio_rl32(s->pb) != MKTAG('H','E','A','D'))
            return AVERROR_INVALIDDATA;
    } else {
        uint32_t info_offset = 0, info_size;
        uint16_t section_count, header_size, i;

        header_size = read16(s); // 6

        avio_skip(s->pb, 4); // Unknown constant 0x00030000
        avio_skip(s->pb, 4); // size of file
        section_count = read16(s);
        avio_skip(s->pb, 2); // padding
        for (i = 0; avio_tell(s->pb) < header_size
                    && !(start && info_offset)
                    && i < section_count; i++) {
            uint16_t flag = read16(s);
            avio_skip(s->pb, 2);
            switch (flag) {
            case 0x4000:
                info_offset = read32(s);
                info_size   = read32(s);
                break;
            case 0x4001:
                avio_skip(s->pb, 4); // seek offset
                avio_skip(s->pb, 4); // seek size
                break;
            case 0x4002:
                start = read32(s) + 8;
                avio_skip(s->pb, 4); //data_size = read32(s);
                break;
            case 0x4003:
                avio_skip(s->pb, 4); // REGN offset
                avio_skip(s->pb, 4); // REGN size
                break;
            }
        }

        if (!info_offset || !start)
            return AVERROR_INVALIDDATA;

        avio_skip(s->pb, info_offset - avio_tell(s->pb));
        pos = avio_tell(s->pb);
        if (avio_rl32(s->pb) != MKTAG('I','N','F','O'))
            return AVERROR_INVALIDDATA;
    }

    size = read32(s);
    if (size < 192)
        return AVERROR_INVALIDDATA;
    avio_skip(s->pb, 4); // unknown
    h1offset = read32(s);
    if (h1offset > size)
        return AVERROR_INVALIDDATA;
    avio_skip(s->pb, 12);
    toffset = read32(s) + 16LL;
    if (toffset > size)
        return AVERROR_INVALIDDATA;

    avio_skip(s->pb, pos + h1offset + 8 - avio_tell(s->pb));
    codec = avio_r8(s->pb);

    switch (codec) {
    case 0: codec = AV_CODEC_ID_PCM_S8_PLANAR;    break;
    case 1: codec = b->little_endian ?
//.........这里部分代码省略.........

static int caf_write_header(AVFormatContext *s)
{
    AVIOContext *pb = s->pb;
    AVCodecContext *enc = s->streams[0]->codec;
    CAFContext *caf = s->priv_data;
    unsigned int codec_tag = ff_codec_get_tag(ff_codec_caf_tags, enc->codec_id);

    switch (enc->codec_id) {
    case CODEC_ID_AAC:
    case CODEC_ID_AC3:
        av_log(s, AV_LOG_ERROR, "muxing codec currently unsupported\n");
        return AVERROR_PATCHWELCOME;
    }

    switch (enc->codec_id) {
    case CODEC_ID_PCM_S8:
    case CODEC_ID_PCM_S16LE:
    case CODEC_ID_PCM_S16BE:
    case CODEC_ID_PCM_S24LE:
    case CODEC_ID_PCM_S24BE:
    case CODEC_ID_PCM_S32LE:
    case CODEC_ID_PCM_S32BE:
    case CODEC_ID_PCM_F32LE:
    case CODEC_ID_PCM_F32BE:
    case CODEC_ID_PCM_F64LE:
    case CODEC_ID_PCM_F64BE:
    case CODEC_ID_PCM_ALAW:
    case CODEC_ID_PCM_MULAW:
        codec_tag = MKTAG('l','p','c','m');
    }

    if (!codec_tag) {
        av_log(s, AV_LOG_ERROR, "unsupported codec\n");
        return AVERROR_INVALIDDATA;
    }

    if (!enc->block_align && !pb->seekable) {
        av_log(s, AV_LOG_ERROR, "Muxing variable packet size not supported on non seekable output\n");
        return AVERROR_INVALIDDATA;
    }

    ffio_wfourcc(pb, "caff"); //< mFileType
    avio_wb16(pb, 1);         //< mFileVersion
    avio_wb16(pb, 0);         //< mFileFlags

    ffio_wfourcc(pb, "desc");                         //< Audio Description chunk
    avio_wb64(pb, 32);                                //< mChunkSize
    avio_wb64(pb, av_dbl2int(enc->sample_rate));      //< mSampleRate
    avio_wl32(pb, codec_tag);                         //< mFormatID
    avio_wb32(pb, codec_flags(enc->codec_id));        //< mFormatFlags
    avio_wb32(pb, enc->block_align);                  //< mBytesPerPacket
    avio_wb32(pb, samples_per_packet(enc->codec_id, enc->channels)); //< mFramesPerPacket
    avio_wb32(pb, enc->channels);                     //< mChannelsPerFrame
    avio_wb32(pb, av_get_bits_per_sample(enc->codec_id)); //< mBitsPerChannel

    if (enc->channel_layout) {
        ffio_wfourcc(pb, "chan");
        avio_wb64(pb, 12);
        ff_mov_write_chan(pb, enc->channel_layout);
    }

    if (enc->codec_id == CODEC_ID_ALAC) {
        ffio_wfourcc(pb, "kuki");
        avio_wb64(pb, 12 + enc->extradata_size);
        avio_write(pb, "\0\0\0\14frmaalac", 12);
        avio_write(pb, enc->extradata, enc->extradata_size);
    } else if (enc->codec_id == CODEC_ID_AMR_NB) {
        ffio_wfourcc(pb, "kuki");
        avio_wb64(pb, 29);
        avio_write(pb, "\0\0\0\14frmasamr", 12);
        avio_wb32(pb, 0x11); /* size */
        avio_write(pb, "samrFFMP", 8);
        avio_w8(pb, 0); /* decoder version */

        avio_wb16(pb, 0x81FF); /* Mode set (all modes for AMR_NB) */
        avio_w8(pb, 0x00); /* Mode change period (no restriction) */
        avio_w8(pb, 0x01); /* Frames per sample */
    } else if (enc->codec_id == CODEC_ID_QDM2) {
        ffio_wfourcc(pb, "kuki");
        avio_wb64(pb, enc->extradata_size);
        avio_write(pb, enc->extradata, enc->extradata_size);
    }

    ffio_wfourcc(pb, "data"); //< Audio Data chunk
    caf->data = avio_tell(pb);
    avio_wb64(pb, -1);        //< mChunkSize
    avio_wb32(pb, 0);         //< mEditCount

    avio_flush(pb);
    return 0;
}

/**
 * @brief read until we found all data needed for decoding
 * @param vst video stream of which to change parameters
 * @param ast video stream of which to change parameters
 * @param myth set if this is a MythTVVideo format file
 * @return 1 if all required codec data was found
 */
static int get_codec_data(AVIOContext *pb, AVStream *vst,
                          AVStream *ast, int myth) {
    nuv_frametype frametype;
    if (!vst && !myth)
        return 1; // no codec data needed
    while (!url_feof(pb)) {
        int size, subtype;
        frametype = avio_r8(pb);
        switch (frametype) {
            case NUV_EXTRADATA:
                subtype = avio_r8(pb);
                avio_skip(pb, 6);
                size = PKTSIZE(avio_rl32(pb));
                if (vst && subtype == 'R') {
                    vst->codec->extradata_size = size;
                    vst->codec->extradata = av_malloc(size);
                    avio_read(pb, vst->codec->extradata, size);
                    size = 0;
                    if (!myth)
                        return 1;
                }
                break;
            case NUV_MYTHEXT:
                avio_skip(pb, 7);
                size = PKTSIZE(avio_rl32(pb));
                if (size != 128 * 4)
                    break;
                avio_rl32(pb); // version
                if (vst) {
                    vst->codec->codec_tag = avio_rl32(pb);
                    vst->codec->codec_id =
                        ff_codec_get_id(ff_codec_bmp_tags, vst->codec->codec_tag);
                    if (vst->codec->codec_tag == MKTAG('R', 'J', 'P', 'G'))
                        vst->codec->codec_id = CODEC_ID_NUV;
                } else
                    avio_skip(pb, 4);

                if (ast) {
                    ast->codec->codec_tag = avio_rl32(pb);
                    ast->codec->sample_rate = avio_rl32(pb);
                    ast->codec->bits_per_coded_sample = avio_rl32(pb);
                    ast->codec->channels = avio_rl32(pb);
                    ast->codec->codec_id =
                        ff_wav_codec_get_id(ast->codec->codec_tag,
                                         ast->codec->bits_per_coded_sample);
                    ast->need_parsing = AVSTREAM_PARSE_FULL;
                } else
                    avio_skip(pb, 4 * 4);

                size -= 6 * 4;
                avio_skip(pb, size);
                return 1;
            case NUV_SEEKP:
                size = 11;
                break;
            default:
                avio_skip(pb, 7);
                size = PKTSIZE(avio_rl32(pb));
                break;
        }
        avio_skip(pb, size);
    }
    return 0;
}

static int xwma_read_header(AVFormatContext *s)
{
    int64_t size;
    int ret;
    uint32_t dpds_table_size = 0;
    uint32_t *dpds_table = 0;
    unsigned int tag;
    AVIOContext *pb = s->pb;
    AVStream *st;
    XWMAContext *xwma = s->priv_data;
    int i;

    /* The following code is mostly copied from wav.c, with some
     * minor alterations.
     */

    /* check RIFF header */
    tag = avio_rl32(pb);
    if (tag != MKTAG('R', 'I', 'F', 'F'))
        return -1;
    avio_rl32(pb); /* file size */
    tag = avio_rl32(pb);
    if (tag != MKTAG('X', 'W', 'M', 'A'))
        return -1;

    /* parse fmt header */
    tag = avio_rl32(pb);
    if (tag != MKTAG('f', 'm', 't', ' '))
        return -1;
    size = avio_rl32(pb);
    st = avformat_new_stream(s, NULL);
    if (!st)
        return AVERROR(ENOMEM);

    ret = ff_get_wav_header(pb, st->codec, size);
    if (ret < 0)
        return ret;
    st->need_parsing = AVSTREAM_PARSE_NONE;

    /* All xWMA files I have seen contained WMAv2 data. If there are files
     * using WMA Pro or some other codec, then we need to figure out the right
     * extradata for that. Thus, ask the user for feedback, but try to go on
     * anyway.
     */
    if (st->codec->codec_id != CODEC_ID_WMAV2) {
        av_log(s, AV_LOG_WARNING, "unexpected codec (tag 0x04%x; id %d)\n",
                              st->codec->codec_tag, st->codec->codec_id);
        av_log_ask_for_sample(s, NULL);
    } else {
        /* In all xWMA files I have seen, there is no extradata. But the WMA
         * codecs require extradata, so we provide our own fake extradata.
         *
         * First, check that there really was no extradata in the header. If
         * there was, then try to use it, after asking the user to provide a
         * sample of this unusual file.
         */
        if (st->codec->extradata_size != 0) {
            /* Surprise, surprise: We *did* get some extradata. No idea
             * if it will work, but just go on and try it, after asking
             * the user for a sample.
             */
            av_log(s, AV_LOG_WARNING, "unexpected extradata (%d bytes)\n",
                                  st->codec->extradata_size);
            av_log_ask_for_sample(s, NULL);
        } else {
            st->codec->extradata_size = 6;
            st->codec->extradata      = av_mallocz(6 + FF_INPUT_BUFFER_PADDING_SIZE);
            if (!st->codec->extradata)
                return AVERROR(ENOMEM);

            /* setup extradata with our experimentally obtained value */
            st->codec->extradata[4] = 31;
        }
    }

    if (!st->codec->channels) {
        av_log(s, AV_LOG_WARNING, "Invalid channel count: %d\n",
               st->codec->channels);
        return AVERROR_INVALIDDATA;
    }
    if (!st->codec->bits_per_coded_sample) {
        av_log(s, AV_LOG_WARNING, "Invalid bits_per_coded_sample: %d\n",
               st->codec->bits_per_coded_sample);
        return AVERROR_INVALIDDATA;
    }

    /* set the sample rate */
    avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);

    /* parse the remaining RIFF chunks */
    for (;;) {
        if (pb->eof_reached)
            return -1;
        /* read next chunk tag */
        tag = avio_rl32(pb);
        size = avio_rl32(pb);
        if (tag == MKTAG('d', 'a', 't', 'a')) {
            /* We assume that the data chunk comes last. */
            break;
        } else if (tag == MKTAG('d','p','d','s')) {
//.........这里部分代码省略.........

 * along with xoreos-tools. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file
 *  Our very own intermediate texture format.
 *  Currently used by NSBTX.
 */

#include "src/common/util.h"
#include "src/common/strutil.h"
#include "src/common/readstream.h"
#include "src/common/error.h"

#include "src/images/xoreositex.h"

static const uint32 kXEOSID = MKTAG('X', 'E', 'O', 'S');
static const uint32 kITEXID = MKTAG('I', 'T', 'E', 'X');

namespace Images {

XEOSITEX::XEOSITEX(Common::SeekableReadStream &xeositex) {
    load(xeositex);
}

XEOSITEX::~XEOSITEX() {
}

void XEOSITEX::load(Common::SeekableReadStream &xeositex) {
    try {

        readHeader(xeositex);

//.........这里部分代码省略.........
    bi = av_malloc(bisize);
    if(!bi) {
        vfw_read_close(s);
        return AVERROR(ENOMEM);
    }
    ret = SendMessage(ctx->hwnd, WM_CAP_GET_VIDEOFORMAT, bisize, (LPARAM) bi);
    if(!ret)
        goto fail_bi;

    dump_bih(s, &bi->bmiHeader);


    if (ctx->video_size) {
        ret = av_parse_video_size(&bi->bmiHeader.biWidth, &bi->bmiHeader.biHeight, ctx->video_size);
        if (ret < 0) {
            av_log(s, AV_LOG_ERROR, "Couldn't parse video size.\n");
            goto fail_bi;
        }
    }
#if FF_API_FORMAT_PARAMETERS
    if (ap->width > 0)
        bi->bmiHeader.biWidth = ap->width;
    if (ap->height > 0)
        bi->bmiHeader.biHeight = ap->height;
#endif

    if (0) {
        /* For testing yet unsupported compressions
         * Copy these values from user-supplied verbose information */
        bi->bmiHeader.biWidth       = 320;
        bi->bmiHeader.biHeight      = 240;
        bi->bmiHeader.biPlanes      = 1;
        bi->bmiHeader.biBitCount    = 12;
        bi->bmiHeader.biCompression = MKTAG('I','4','2','0');
        bi->bmiHeader.biSizeImage   = 115200;
        dump_bih(s, &bi->bmiHeader);
    }

    ret = SendMessage(ctx->hwnd, WM_CAP_SET_VIDEOFORMAT, bisize, (LPARAM) bi);
    if(!ret) {
        av_log(s, AV_LOG_ERROR, "Could not set Video Format.\n");
        goto fail_bi;
    }

    biCompression = bi->bmiHeader.biCompression;
    biBitCount = bi->bmiHeader.biBitCount;

    av_free(bi);

    /* Set sequence setup */
    ret = SendMessage(ctx->hwnd, WM_CAP_GET_SEQUENCE_SETUP, sizeof(cparms),
                      (LPARAM) &cparms);
    if(!ret)
        goto fail_io;

    dump_captureparms(s, &cparms);

    cparms.fYield = 1; // Spawn a background thread
    cparms.dwRequestMicroSecPerFrame =
                               (fps.den*1000000) / fps.num;
    cparms.fAbortLeftMouse = 0;
    cparms.fAbortRightMouse = 0;
    cparms.fCaptureAudio = 0;
    cparms.vKeyAbort = 0;

    ret = SendMessage(ctx->hwnd, WM_CAP_SET_SEQUENCE_SETUP, sizeof(cparms),

bool StuffItArchive::open(const Common::String &filename) {
	close();

	_stream = SearchMan.createReadStreamForMember(filename);

	if (!_stream)
		return false;

	uint32 tag = _stream->readUint32BE();

	// Check all the possible FourCC's
	bool found = false;
	for (int i = 0; i < ARRAYSIZE(s_magicNumbers); i++) {
		if (tag == s_magicNumbers[i]) {
			found = true;
			break;
		}
	}

	// Didn't find one, let's bail out
	if (!found) {
		close();
		return false;
	}

	/* uint16 fileCount = */ _stream->readUint16BE();
	/* uint32 archiveSize = */ _stream->readUint32BE();

	// Some sort of second magic number
	if (_stream->readUint32BE() != MKTAG('r', 'L', 'a', 'u')) {
		close();
		return false;
	}

	/* byte version = */ _stream->readByte(); // meaning not clear

	_stream->skip(7); // unknown

	while (_stream->pos() < _stream->size() && !_stream->eos()) {
		byte resForkCompression = _stream->readByte();
		byte dataForkCompression = _stream->readByte();

		byte fileNameLength = _stream->readByte();
		Common::String name;

		for (byte i = 0; i < fileNameLength; i++)
			name += (char)_stream->readByte();

		// Skip remaining bytes
		_stream->skip(63 - fileNameLength);

		/* uint32 fileType = */ _stream->readUint32BE();
		/* uint32 fileCreator = */ _stream->readUint32BE();
		/* uint16 finderFlags = */ _stream->readUint16BE();
		/* uint32 creationDate = */ _stream->readUint32BE();
		/* uint32 modificationDate = */ _stream->readUint32BE();
		uint32 resForkUncompressedSize = _stream->readUint32BE();
		uint32 dataForkUncompressedSize = _stream->readUint32BE();
		uint32 resForkCompressedSize = _stream->readUint32BE();
		uint32 dataForkCompressedSize = _stream->readUint32BE();
		/* uint16 resForkCRC = */ _stream->readUint16BE();
		/* uint16 dataForkCRC = */ _stream->readUint16BE();
		_stream->skip(6); // unknown
		/* uint16 headerCRC = */ _stream->readUint16BE();

		// Ignore directories for now
		if (dataForkCompression == 32 || dataForkCompression == 33)
			continue;

		if (dataForkUncompressedSize != 0) {
			// We have a data fork

			FileEntry entry;
			entry.compression = dataForkCompression;
			entry.uncompressedSize = dataForkUncompressedSize;
			entry.compressedSize = dataForkCompressedSize;
			entry.offset = _stream->pos() + resForkCompressedSize;
			_map[name] = entry;

			debug(0, "StuffIt file '%s', Compression = %d", name.c_str(), entry.compression);
		}

		if (resForkUncompressedSize != 0) {
			// We have a resource fork

			// Add a .rsrc extension so we know it's the resource fork
			name += ".rsrc";

			FileEntry entry;
			entry.compression = resForkCompression;
			entry.uncompressedSize = resForkUncompressedSize;
			entry.compressedSize = resForkCompressedSize;
			entry.offset = _stream->pos();
			_map[name] = entry;

			debug(0, "StuffIt file '%s', Compression = %d", name.c_str(), entry.compression);
		}

		// Go to the next entry
		_stream->skip(dataForkCompressedSize + resForkCompressedSize);
//.........这里部分代码省略.........

STDMETHODIMP CDecAvcodec::InitDecoder(AVCodecID codec, const CMediaType *pmt)
{
  DestroyDecoder();
  DbgLog((LOG_TRACE, 10, L"Initializing ffmpeg for codec %S", avcodec_get_name(codec)));

  BITMAPINFOHEADER *pBMI = NULL;
  videoFormatTypeHandler((const BYTE *)pmt->Format(), pmt->FormatType(), &pBMI);

  m_pAVCodec = avcodec_find_decoder(codec);
  CheckPointer(m_pAVCodec, VFW_E_UNSUPPORTED_VIDEO);

  m_pAVCtx = avcodec_alloc_context3(m_pAVCodec);
  CheckPointer(m_pAVCtx, E_POINTER);

  if(codec == AV_CODEC_ID_MPEG1VIDEO || codec == AV_CODEC_ID_MPEG2VIDEO || pmt->subtype == FOURCCMap(MKTAG('H','2','6','4')) || pmt->subtype == FOURCCMap(MKTAG('h','2','6','4'))) {
    m_pParser = av_parser_init(codec);
  }

  DWORD dwDecFlags = m_pCallback->GetDecodeFlags();

  LONG biRealWidth = pBMI->biWidth, biRealHeight = pBMI->biHeight;
  if (pmt->formattype == FORMAT_VideoInfo || pmt->formattype == FORMAT_MPEGVideo) {
    VIDEOINFOHEADER *vih = (VIDEOINFOHEADER *)pmt->Format();
    if (vih->rcTarget.right != 0 && vih->rcTarget.bottom != 0) {
      biRealWidth  = vih->rcTarget.right;
      biRealHeight = vih->rcTarget.bottom;
    }
  } else if (pmt->formattype == FORMAT_VideoInfo2 || pmt->formattype == FORMAT_MPEG2Video) {
    VIDEOINFOHEADER2 *vih2 = (VIDEOINFOHEADER2 *)pmt->Format();
    if (vih2->rcTarget.right != 0 && vih2->rcTarget.bottom != 0) {
      biRealWidth  = vih2->rcTarget.right;
      biRealHeight = vih2->rcTarget.bottom;
    }
  }

  m_pAVCtx->codec_id              = codec;
  m_pAVCtx->codec_tag             = pBMI->biCompression;
  m_pAVCtx->coded_width           = pBMI->biWidth;
  m_pAVCtx->coded_height          = abs(pBMI->biHeight);
  m_pAVCtx->bits_per_coded_sample = pBMI->biBitCount;
  m_pAVCtx->error_concealment     = FF_EC_GUESS_MVS | FF_EC_DEBLOCK;
  m_pAVCtx->err_recognition       = AV_EF_CAREFUL;
  m_pAVCtx->workaround_bugs       = FF_BUG_AUTODETECT;
  m_pAVCtx->refcounted_frames     = 1;

  if (codec == AV_CODEC_ID_H264)
    m_pAVCtx->flags2             |= CODEC_FLAG2_SHOW_ALL;

  // Setup threading
  int thread_type = getThreadFlags(codec);
  if (thread_type) {
    // Thread Count. 0 = auto detect
    int thread_count = m_pSettings->GetNumThreads();
    if (thread_count == 0) {
      SYSTEM_INFO systemInfo;
      GetSystemInfo(&systemInfo);
      thread_count = systemInfo.dwNumberOfProcessors * 3 / 2;
    }

    m_pAVCtx->thread_count = max(1, min(thread_count, AVCODEC_MAX_THREADS));
    m_pAVCtx->thread_type = thread_type;
  } else {
    m_pAVCtx->thread_count = 1;
  }

  if (dwDecFlags & LAV_VIDEO_DEC_FLAG_NO_MT) {
    m_pAVCtx->thread_count = 1;
  }

  m_pFrame = av_frame_alloc();
  CheckPointer(m_pFrame, E_POINTER);

  m_h264RandomAccess.SetAVCNALSize(0);

  // Process Extradata
  BYTE *extra = NULL;
  size_t extralen = 0;
  getExtraData(*pmt, NULL, &extralen);

  BOOL bH264avc = FALSE;
  if (extralen > 0) {
    DbgLog((LOG_TRACE, 10, L"-> Processing extradata of %d bytes", extralen));
    // Reconstruct AVC1 extradata format
    if (pmt->formattype == FORMAT_MPEG2Video && (m_pAVCtx->codec_tag == MAKEFOURCC('a','v','c','1') || m_pAVCtx->codec_tag == MAKEFOURCC('A','V','C','1') || m_pAVCtx->codec_tag == MAKEFOURCC('C','C','V','1'))) {
      MPEG2VIDEOINFO *mp2vi = (MPEG2VIDEOINFO *)pmt->Format();
      extralen += 7;
      extra = (uint8_t *)av_mallocz(extralen + FF_INPUT_BUFFER_PADDING_SIZE);
      extra[0] = 1;
      extra[1] = (BYTE)mp2vi->dwProfile;
      extra[2] = 0;
      extra[3] = (BYTE)mp2vi->dwLevel;
      extra[4] = (BYTE)(mp2vi->dwFlags ? mp2vi->dwFlags : 2) - 1;

      // Actually copy the metadata into our new buffer
      size_t actual_len;
      getExtraData(*pmt, extra+6, &actual_len);

      // Count the number of SPS/PPS in them and set the length
      // We'll put them all into one block and add a second block with 0 elements afterwards
      // The parsing logic does not care what type they are, it just expects 2 blocks.
//.........这里部分代码省略.........

bool SmackerDecoder::loadStream(Common::SeekableReadStream *stream) {
	close();

	_fileStream = stream;

	// Read in the Smacker header
	_header.signature = _fileStream->readUint32BE();

	if (_header.signature != MKTAG('S', 'M', 'K', '2') && _header.signature != MKTAG('S', 'M', 'K', '4'))
		return false;

	uint32 width = _fileStream->readUint32LE();
	uint32 height = _fileStream->readUint32LE();
	uint32 frameCount = _fileStream->readUint32LE();
	int32 frameDelay = _fileStream->readSint32LE();

	// frame rate contains 2 digits after the comma, so 1497 is actually 14.97 fps
	Common::Rational frameRate;
	if (frameDelay > 0)
		frameRate = Common::Rational(1000, frameDelay);
	else if (frameDelay < 0)
		frameRate = Common::Rational(100000, -frameDelay);
	else
		frameRate = 1000;

	// Flags are determined by which bit is set, which can be one of the following:
	// 0 - set to 1 if file contains a ring frame.
	// 1 - set to 1 if file is Y-interlaced
	// 2 - set to 1 if file is Y-doubled
	// If bits 1 or 2 are set, the frame should be scaled to twice its height
	// before it is displayed.
	_header.flags = _fileStream->readUint32LE();

	SmackerVideoTrack *videoTrack = createVideoTrack(width, height, frameCount, frameRate, _header.flags, _header.signature);
	addTrack(videoTrack);

	// TODO: should we do any extra processing for Smacker files with ring frames?

	// TODO: should we do any extra processing for Y-doubled videos? Are they the
	// same as Y-interlaced videos?

	uint32 i;
	for (i = 0; i < 7; ++i)
		_header.audioSize[i] = _fileStream->readUint32LE();

	_header.treesSize = _fileStream->readUint32LE();
	_header.mMapSize = _fileStream->readUint32LE();
	_header.mClrSize = _fileStream->readUint32LE();
	_header.fullSize = _fileStream->readUint32LE();
	_header.typeSize = _fileStream->readUint32LE();

	for (i = 0; i < 7; ++i) {
		// AudioRate - Frequency and format information for each sound track, up to 7 audio tracks.
		// The 32 constituent bits have the following meaning:
		// * bit 31 - indicates Huffman + DPCM compression
		// * bit 30 - indicates that audio data is present for this track
		// * bit 29 - 1 = 16-bit audio; 0 = 8-bit audio
		// * bit 28 - 1 = stereo audio; 0 = mono audio
		// * bit 27 - indicates Bink RDFT compression
		// * bit 26 - indicates Bink DCT compression
		// * bits 25-24 - unused
		// * bits 23-0 - audio sample rate
		uint32 audioInfo = _fileStream->readUint32LE();
		_header.audioInfo[i].hasAudio = audioInfo & 0x40000000;
		_header.audioInfo[i].is16Bits = audioInfo & 0x20000000;
		_header.audioInfo[i].isStereo = audioInfo & 0x10000000;
		_header.audioInfo[i].sampleRate = audioInfo & 0xFFFFFF;

		if (audioInfo & 0x8000000)
			_header.audioInfo[i].compression = kCompressionRDFT;
		else if (audioInfo & 0x4000000)
			_header.audioInfo[i].compression = kCompressionDCT;
		else if (audioInfo & 0x80000000)
			_header.audioInfo[i].compression = kCompressionDPCM;
		else
			_header.audioInfo[i].compression = kCompressionNone;

		if (_header.audioInfo[i].hasAudio) {
			if (_header.audioInfo[i].compression == kCompressionRDFT || _header.audioInfo[i].compression == kCompressionDCT)
				warning("Unhandled Smacker v2 audio compression");

			addTrack(new SmackerAudioTrack(_header.audioInfo[i], _soundType));
		}
	}

	_header.dummy = _fileStream->readUint32LE();

	_frameSizes = new uint32[frameCount];
	for (i = 0; i < frameCount; ++i)
		_frameSizes[i] = _fileStream->readUint32LE();

	_frameTypes = new byte[frameCount];
	for (i = 0; i < frameCount; ++i)
		_frameTypes[i] = _fileStream->readByte();

	byte *huffmanTrees = (byte *) malloc(_header.treesSize);
	_fileStream->read(huffmanTrees, _header.treesSize);

	Common::BitStream8LSB bs(new Common::MemoryReadStream(huffmanTrees, _header.treesSize, DisposeAfterUse::YES), true);
	videoTrack->readTrees(bs, _header.mMapSize, _header.mClrSize, _header.fullSize, _header.typeSize);
//.........这里部分代码省略.........