static int SkipFile(struct stream *s, int *count, rar_file_t ***file,
                    const rar_block_t *hdr, const char *volume_mrl)
{
    int min_size = 7+21;
    if (hdr->flags & RAR_BLOCK_FILE_HAS_HIGH)
        min_size += 8;
    if (hdr->size < (unsigned)min_size)
        return -1;

    bstr data = stream_peek(s, min_size);
    if (data.len < min_size)
        return -1;
    const uint8_t *peek = (uint8_t *)data.start;

    /* */
    uint32_t file_size_low = AV_RL32(&peek[7+4]);
    uint8_t  method = peek[7+18];
    uint16_t name_size = AV_RL16(&peek[7+19]);
    uint32_t file_size_high = 0;
    if (hdr->flags & RAR_BLOCK_FILE_HAS_HIGH)
        file_size_high = AV_RL32(&peek[7+29]);
    const uint64_t file_size = ((uint64_t)file_size_high << 32) | file_size_low;

    char *name = calloc(1, name_size + 1);
    if (!name)
        return -1;

    const int name_offset = (hdr->flags & RAR_BLOCK_FILE_HAS_HIGH) ? (7+33) : (7+25);
    if (name_offset + name_size <= hdr->size) {
        const int max_size = name_offset + name_size;
        bstr namedata = stream_peek(s, max_size);
        if (namedata.len < max_size) {
            free(name);
            return -1;
        }
        memcpy(name, &namedata.start[name_offset], name_size);
    }

    rar_file_t *current = NULL;
    if (method != 0x30) {
        MP_WARN(s, "Ignoring compressed file %s (method=0x%2.2x)\n", name, method);
        goto exit;
    }

    /* */
    if( *count > 0 )
        current = (*file)[*count - 1];

    if (current &&
        (current->is_complete ||
          strcmp(current->name, name) ||
          (hdr->flags & RAR_BLOCK_FILE_HAS_PREVIOUS) == 0))
        current = NULL;

    if (!current) {
        if (hdr->flags & RAR_BLOCK_FILE_HAS_PREVIOUS)
            goto exit;
        current = calloc(1, sizeof(*current));
        if (!current)
            goto exit;
        MP_TARRAY_APPEND(NULL, *file, *count, current);

        current->name = name;
        current->size = file_size;
        current->is_complete = false;
        current->real_size = 0;
        current->chunk_count = 0;
        current->chunk = NULL;

        name = NULL;
    }

    /* Append chunks */
    rar_file_chunk_t *chunk = malloc(sizeof(*chunk));
    if (chunk) {
        chunk->mrl = strdup(volume_mrl);
        chunk->offset = stream_tell(s) + hdr->size;
        chunk->size = hdr->add_size;
        chunk->cummulated_size = 0;
        if (current->chunk_count > 0) {
            rar_file_chunk_t *previous = current->chunk[current->chunk_count-1];

            chunk->cummulated_size += previous->cummulated_size +
                                      previous->size;
        }

        MP_TARRAY_APPEND(NULL, current->chunk, current->chunk_count, chunk);

        current->real_size += hdr->add_size;
    }
    if ((hdr->flags & RAR_BLOCK_FILE_HAS_NEXT) == 0)
        current->is_complete = true;

exit:
    /* */
    free(name);

    /* We stop on the first non empty file if we cannot seek */
    if (current) {
        bool can_seek = s->end_pos > 0;
//.........这里部分代码省略.........

static int str_read_packet(AVFormatContext *s,
                           AVPacket *ret_pkt)
{
    AVIOContext *pb = s->pb;
    StrDemuxContext *str = s->priv_data;
    unsigned char sector[RAW_CD_SECTOR_SIZE];
    int channel;
    AVPacket *pkt;
    AVStream *st;

    while (1) {

        if (avio_read(pb, sector, RAW_CD_SECTOR_SIZE) != RAW_CD_SECTOR_SIZE)
            return AVERROR(EIO);

        channel = sector[0x11];
        if (channel >= 32)
            return AVERROR_INVALIDDATA;

        switch (sector[0x12] & CDXA_TYPE_MASK) {

        case CDXA_TYPE_DATA:
        case CDXA_TYPE_VIDEO:
            {

                int current_sector = AV_RL16(&sector[0x1C]);
                int sector_count   = AV_RL16(&sector[0x1E]);
                int frame_size = AV_RL32(&sector[0x24]);

                if(!(   frame_size>=0
                     && current_sector < sector_count
                     && sector_count*VIDEO_DATA_CHUNK_SIZE >=frame_size)){
                    av_log(s, AV_LOG_ERROR, "Invalid parameters %d %d %d\n", current_sector, sector_count, frame_size);
                    break;
                }

                if(str->channels[channel].video_stream_index < 0){
                    /* allocate a new AVStream */
                    st = avformat_new_stream(s, NULL);
                    if (!st)
                        return AVERROR(ENOMEM);
                    avpriv_set_pts_info(st, 64, 1, 15);

                    str->channels[channel].video_stream_index = st->index;

                    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
                    st->codec->codec_id   = CODEC_ID_MDEC;
                    st->codec->codec_tag  = 0;  /* no fourcc */
                    st->codec->width      = AV_RL16(&sector[0x28]);
                    st->codec->height     = AV_RL16(&sector[0x2A]);
                }

                /* if this is the first sector of the frame, allocate a pkt */
                pkt = &str->channels[channel].tmp_pkt;

                if(pkt->size != sector_count*VIDEO_DATA_CHUNK_SIZE){
                    if(pkt->data)
                        av_log(s, AV_LOG_ERROR, "missmatching sector_count\n");
                    av_free_packet(pkt);
                    if (av_new_packet(pkt, sector_count*VIDEO_DATA_CHUNK_SIZE))
                        return AVERROR(EIO);

                    pkt->pos= avio_tell(pb) - RAW_CD_SECTOR_SIZE;
                    pkt->stream_index =
                        str->channels[channel].video_stream_index;
                }

                memcpy(pkt->data + current_sector*VIDEO_DATA_CHUNK_SIZE,
                       sector + VIDEO_DATA_HEADER_SIZE,
                       VIDEO_DATA_CHUNK_SIZE);

                if (current_sector == sector_count-1) {
                    pkt->size= frame_size;
                    *ret_pkt = *pkt;
                    pkt->data= NULL;
                    pkt->size= -1;
                    return 0;
                }

            }
            break;

        case CDXA_TYPE_AUDIO:
            if(str->channels[channel].audio_stream_index < 0){
                int fmt = sector[0x13];
                /* allocate a new AVStream */
                st = avformat_new_stream(s, NULL);
                if (!st)
                    return AVERROR(ENOMEM);

                str->channels[channel].audio_stream_index = st->index;

                st->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
                st->codec->codec_id    = CODEC_ID_ADPCM_XA;
                st->codec->codec_tag   = 0;  /* no fourcc */
                st->codec->channels    = (fmt&1)?2:1;
                st->codec->sample_rate = (fmt&4)?18900:37800;
            //    st->codec->bit_rate = 0; //FIXME;
                st->codec->block_align = 128;

//.........这里部分代码省略.........

static int decode_rle(CamtasiaContext *c, unsigned int srcsize)
{
    unsigned char *src = c->decomp_buf;
    unsigned char *output, *output_end;
    int p1, p2, line=c->height, pos=0, i;
    uint16_t pix16;
    uint32_t pix32;

    output = c->pic.data[0] + (c->height - 1) * c->pic.linesize[0];
    output_end = c->pic.data[0] + (c->height) * c->pic.linesize[0];
    while(src < c->decomp_buf + srcsize) {
        p1 = *src++;
        if(p1 == 0) { //Escape code
            p2 = *src++;
            if(p2 == 0) { //End-of-line
                output = c->pic.data[0] + (--line) * c->pic.linesize[0];
                if (line < 0)
                    return -1;
                pos = 0;
                continue;
            } else if(p2 == 1) { //End-of-picture
                return 0;
            } else if(p2 == 2) { //Skip
                p1 = *src++;
                p2 = *src++;
                line -= p2;
                if (line < 0)
                    return -1;
                pos += p1;
                output = c->pic.data[0] + line * c->pic.linesize[0] + pos * (c->bpp / 8);
                continue;
            }
            // Copy data
            if (output + p2 * (c->bpp / 8) > output_end) {
                src += p2 * (c->bpp / 8);
                continue;
            }
            if ((c->bpp == 8) || (c->bpp == 24)) {
                for(i = 0; i < p2 * (c->bpp / 8); i++) {
                    *output++ = *src++;
                }
                // RLE8 copy is actually padded - and runs are not!
                if(c->bpp == 8 && (p2 & 1)) {
                    src++;
                }
            } else if (c->bpp == 16) {
                for(i = 0; i < p2; i++) {
                    pix16 = AV_RL16(src);
                    src += 2;
                    *(uint16_t*)output = pix16;
                    output += 2;
                }
            } else if (c->bpp == 32) {
                for(i = 0; i < p2; i++) {
                    pix32 = AV_RL32(src);
                    src += 4;
                    *(uint32_t*)output = pix32;
                    output += 4;
                }
            }
            pos += p2;
        } else { //Run of pixels
            int pix[4]; //original pixel
            switch(c->bpp){
            case  8: pix[0] = *src++;
                     break;
            case 16: pix16 = AV_RL16(src);
                     src += 2;
                     *(uint16_t*)pix = pix16;
                     break;
            case 24: pix[0] = *src++;
                     pix[1] = *src++;
                     pix[2] = *src++;
                     break;
            case 32: pix32 = AV_RL32(src);
                     src += 4;
                     *(uint32_t*)pix = pix32;
                     break;
            }
            if (output + p1 * (c->bpp / 8) > output_end)
                continue;
            for(i = 0; i < p1; i++) {
                switch(c->bpp){
                case  8: *output++ = pix[0];
                         break;
                case 16: *(uint16_t*)output = pix16;
                         output += 2;
                         break;
                case 24: *output++ = pix[0];
                         *output++ = pix[1];
                         *output++ = pix[2];
                         break;
                case 32: *(uint32_t*)output = pix32;
                         output += 4;
                         break;
                }
            }
            pos += p1;
        }
    }
//.........这里部分代码省略.........

static int flic_decode_frame_15_16BPP(AVCodecContext *avctx,
                                      void *data, int *data_size,
                                      const uint8_t *buf, int buf_size)
{
    /* Note, the only difference between the 15Bpp and 16Bpp */
    /* Format is the pixel format, the packets are processed the same. */
    FlicDecodeContext *s = avctx->priv_data;

    int stream_ptr = 0;
    int pixel_ptr;
    unsigned char palette_idx1;

    unsigned int frame_size;
    int num_chunks;

    unsigned int chunk_size;
    int chunk_type;

    int i, j;

    int lines;
    int compressed_lines;
    signed short line_packets;
    int y_ptr;
    int byte_run;
    int pixel_skip;
    int pixel_countdown;
    unsigned char *pixels;
    int pixel;
    unsigned int pixel_limit;

    s->frame.reference = 1;
    s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
    if (avctx->reget_buffer(avctx, &s->frame) < 0) {
        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
        return -1;
    }

    pixels = s->frame.data[0];
    pixel_limit = s->avctx->height * s->frame.linesize[0];

    frame_size = AV_RL32(&buf[stream_ptr]);
    stream_ptr += 6;  /* skip the magic number */
    num_chunks = AV_RL16(&buf[stream_ptr]);
    stream_ptr += 10;  /* skip padding */

    frame_size -= 16;

    /* iterate through the chunks */
    while ((frame_size > 0) && (num_chunks > 0)) {
        chunk_size = AV_RL32(&buf[stream_ptr]);
        stream_ptr += 4;
        chunk_type = AV_RL16(&buf[stream_ptr]);
        stream_ptr += 2;

        switch (chunk_type) {
        case FLI_256_COLOR:
        case FLI_COLOR:
            /* For some reason, it seems that non-palettized flics do
             * include one of these chunks in their first frame.
             * Why I do not know, it seems rather extraneous. */
/*            av_log(avctx, AV_LOG_ERROR, "Unexpected Palette chunk %d in non-paletised FLC\n",chunk_type);*/
            stream_ptr = stream_ptr + chunk_size - 6;
            break;

        case FLI_DELTA:
        case FLI_DTA_LC:
            y_ptr = 0;
            compressed_lines = AV_RL16(&buf[stream_ptr]);
            stream_ptr += 2;
            while (compressed_lines > 0) {
                line_packets = AV_RL16(&buf[stream_ptr]);
                stream_ptr += 2;
                if (line_packets < 0) {
                    line_packets = -line_packets;
                    y_ptr += line_packets * s->frame.linesize[0];
                } else {
                    compressed_lines--;
                    pixel_ptr = y_ptr;
                    CHECK_PIXEL_PTR(0);
                    pixel_countdown = s->avctx->width;
                    for (i = 0; i < line_packets; i++) {
                        /* account for the skip bytes */
                        pixel_skip = buf[stream_ptr++];
                        pixel_ptr += (pixel_skip*2); /* Pixel is 2 bytes wide */
                        pixel_countdown -= pixel_skip;
                        byte_run = (signed char)(buf[stream_ptr++]);
                        if (byte_run < 0) {
                            byte_run = -byte_run;
                            pixel    = AV_RL16(&buf[stream_ptr]);
                            stream_ptr += 2;
                            CHECK_PIXEL_PTR(2 * byte_run);
                            for (j = 0; j < byte_run; j++, pixel_countdown -= 2) {
                                *((signed short*)(&pixels[pixel_ptr])) = pixel;
                                pixel_ptr += 2;
                            }
                        } else {
                            CHECK_PIXEL_PTR(2 * byte_run);
                            for (j = 0; j < byte_run; j++, pixel_countdown--) {
                                *((signed short*)(&pixels[pixel_ptr])) = AV_RL16(&buf[stream_ptr]);
//.........这里部分代码省略.........

/**
 * Decode Smacker audio data
 */
static int smka_decode_frame(AVCodecContext *avctx, void *data,
                             int *got_frame_ptr, AVPacket *avpkt)
{
    SmackerAudioContext *s = avctx->priv_data;
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    GetBitContext gb;
    HuffContext h[4];
    VLC vlc[4];
    int16_t *samples;
    uint8_t *samples8;
    int val;
    int i, res, ret;
    int unp_size;
    int bits, stereo;
    int pred[2] = {0, 0};

    if (buf_size <= 4) {
        av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
        return AVERROR(EINVAL);
    }

    unp_size = AV_RL32(buf);

    init_get_bits(&gb, buf + 4, (buf_size - 4) * 8);

    if(!get_bits1(&gb)){
        av_log(avctx, AV_LOG_INFO, "Sound: no data\n");
        *got_frame_ptr = 0;
        return 1;
    }
    stereo = get_bits1(&gb);
    bits = get_bits1(&gb);
    if (stereo ^ (avctx->channels != 1)) {
        av_log(avctx, AV_LOG_ERROR, "channels mismatch\n");
        return AVERROR(EINVAL);
    }
    if (bits && avctx->sample_fmt == AV_SAMPLE_FMT_U8) {
        av_log(avctx, AV_LOG_ERROR, "sample format mismatch\n");
        return AVERROR(EINVAL);
    }

    /* get output buffer */
    s->frame.nb_samples = unp_size / (avctx->channels * (bits + 1));
    if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return ret;
    }
    samples  = (int16_t *)s->frame.data[0];
    samples8 =            s->frame.data[0];

    memset(vlc, 0, sizeof(VLC) * 4);
    memset(h, 0, sizeof(HuffContext) * 4);
    // Initialize
    for(i = 0; i < (1 << (bits + stereo)); i++) {
        h[i].length = 256;
        h[i].maxlength = 0;
        h[i].current = 0;
        h[i].bits = av_mallocz(256 * 4);
        h[i].lengths = av_mallocz(256 * sizeof(int));
        h[i].values = av_mallocz(256 * sizeof(int));
        skip_bits1(&gb);
        smacker_decode_tree(&gb, &h[i], 0, 0);
        skip_bits1(&gb);
        if(h[i].current > 1) {
            res = init_vlc(&vlc[i], SMKTREE_BITS, h[i].length,
                    h[i].lengths, sizeof(int), sizeof(int),
                    h[i].bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);
            if(res < 0) {
                av_log(avctx, AV_LOG_ERROR, "Cannot build VLC table\n");
                return -1;
            }
        }
    }
    if(bits) { //decode 16-bit data
        for(i = stereo; i >= 0; i--)
            pred[i] = av_bswap16(get_bits(&gb, 16));
        for(i = 0; i <= stereo; i++)
            *samples++ = pred[i];
        for(; i < unp_size / 2; i++) {
            if(get_bits_left(&gb)<0)
                return -1;
            if(i & stereo) {
                if(vlc[2].table)
                    res = get_vlc2(&gb, vlc[2].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                val  = h[2].values[res];
                if(vlc[3].table)
                    res = get_vlc2(&gb, vlc[3].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                val |= h[3].values[res] << 8;
                pred[1] += sign_extend(val, 16);
                *samples++ = av_clip_int16(pred[1]);
            } else {
                if(vlc[0].table)
//.........这里部分代码省略.........

static int decode_frame(AVCodecContext *avctx,
                        void *data,
                        int *data_size,
                        AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size       = avpkt->size;
    DPXContext *const s = avctx->priv_data;
    AVFrame *picture  = data;
    AVFrame *const p = &s->picture;
    uint8_t *ptr;

    int magic_num, offset, endian;
    int x, y;
    int w, h, stride, bits_per_color, descriptor, elements, target_packet_size, source_packet_size;

    unsigned int rgbBuffer;

    magic_num = AV_RB32(buf);
    buf += 4;

    /* Check if the files "magic number" is "SDPX" which means it uses
     * big-endian or XPDS which is for little-endian files */
    if (magic_num == AV_RL32("SDPX")) {
        endian = 0;
    } else if (magic_num == AV_RB32("SDPX")) {
        endian = 1;
    } else {
        av_log(avctx, AV_LOG_ERROR, "DPX marker not found\n");
        return -1;
    }

    offset = read32(&buf, endian);
    // Need to end in 0x304 offset from start of file
    buf = avpkt->data + 0x304;
    w = read32(&buf, endian);
    h = read32(&buf, endian);

    // Need to end in 0x320 to read the descriptor
    buf += 20;
    descriptor = buf[0];

    // Need to end in 0x323 to read the bits per color
    buf += 3;
    avctx->bits_per_raw_sample =
    bits_per_color = buf[0];

    switch (descriptor) {
        case 51: // RGBA
            elements = 4;
            break;
        case 50: // RGB
            elements = 3;
            break;
        default:
            av_log(avctx, AV_LOG_ERROR, "Unsupported descriptor %d\n", descriptor);
            return -1;
    }

    switch (bits_per_color) {
        case 8:
            if (elements == 4) {
                avctx->pix_fmt = PIX_FMT_RGBA;
            } else {
                avctx->pix_fmt = PIX_FMT_RGB24;
            }
            source_packet_size = elements;
            target_packet_size = elements;
            break;
        case 10:
            avctx->pix_fmt = PIX_FMT_RGB48;
            target_packet_size = 6;
            source_packet_size = elements * 2;
            break;
        case 12:
        case 16:
            if (endian) {
                avctx->pix_fmt = PIX_FMT_RGB48BE;
            } else {
                avctx->pix_fmt = PIX_FMT_RGB48LE;
            }
            target_packet_size = 6;
            source_packet_size = elements * 2;
            break;
        default:
            av_log(avctx, AV_LOG_ERROR, "Unsupported color depth : %d\n", bits_per_color);
            return -1;
    }

    if (s->picture.data[0])
        avctx->release_buffer(avctx, &s->picture);
    if (avcodec_check_dimensions(avctx, w, h))
        return -1;
    if (w != avctx->width || h != avctx->height)
        avcodec_set_dimensions(avctx, w, h);
    if (avctx->get_buffer(avctx, p) < 0) {
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return -1;
    }

//.........这里部分代码省略.........

static int fourxm_read_header(AVFormatContext *s)
{
    AVIOContext *pb = s->pb;
    unsigned int fourcc_tag;
    unsigned int size;
    int header_size;
    FourxmDemuxContext *fourxm = s->priv_data;
    unsigned char *header;
    int i, ret;
    AVStream *st;

    fourxm->track_count = 0;
    fourxm->tracks = NULL;
    fourxm->fps = 1.0;

    /* skip the first 3 32-bit numbers */
    avio_skip(pb, 12);

    /* check for LIST-HEAD */
    GET_LIST_HEADER();
    header_size = size - 4;
    if (fourcc_tag != HEAD_TAG || header_size < 0)
        return AVERROR_INVALIDDATA;

    /* allocate space for the header and load the whole thing */
    header = av_malloc(header_size);
    if (!header)
        return AVERROR(ENOMEM);
    if (avio_read(pb, header, header_size) != header_size){
        av_free(header);
        return AVERROR(EIO);
    }

    /* take the lazy approach and search for any and all vtrk and strk chunks */
    for (i = 0; i < header_size - 8; i++) {
        fourcc_tag = AV_RL32(&header[i]);
        size = AV_RL32(&header[i + 4]);
        if (size > header_size - i - 8 && (fourcc_tag == vtrk_TAG || fourcc_tag == strk_TAG)) {
            av_log(s, AV_LOG_ERROR, "chunk larger than array %d>%d\n", size, header_size - i - 8);
            return AVERROR_INVALIDDATA;
        }

        if (fourcc_tag == std__TAG) {
            fourxm->fps = av_int2float(AV_RL32(&header[i + 12]));
        } else if (fourcc_tag == vtrk_TAG) {
            /* check that there is enough data */
            if (size != vtrk_SIZE) {
                ret= AVERROR_INVALIDDATA;
                goto fail;
            }
            fourxm->width  = AV_RL32(&header[i + 36]);
            fourxm->height = AV_RL32(&header[i + 40]);

            /* allocate a new AVStream */
            st = avformat_new_stream(s, NULL);
            if (!st){
                ret= AVERROR(ENOMEM);
                goto fail;
            }
            avpriv_set_pts_info(st, 60, 1, fourxm->fps);

            fourxm->video_stream_index = st->index;

            st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
            st->codec->codec_id = AV_CODEC_ID_4XM;
            st->codec->extradata_size = 4;
            st->codec->extradata = av_malloc(4);
            AV_WL32(st->codec->extradata, AV_RL32(&header[i + 16]));
            st->codec->width  = fourxm->width;
            st->codec->height = fourxm->height;

            i += 8 + size;
        } else if (fourcc_tag == strk_TAG) {
            int current_track;
            /* check that there is enough data */
            if (size != strk_SIZE) {
                ret= AVERROR_INVALIDDATA;
                goto fail;
            }
            current_track = AV_RL32(&header[i + 8]);
            if((unsigned)current_track >= UINT_MAX / sizeof(AudioTrack) - 1){
                av_log(s, AV_LOG_ERROR, "current_track too large\n");
                ret = AVERROR_INVALIDDATA;
                goto fail;
            }
            if (current_track + 1 > fourxm->track_count) {
                fourxm->tracks = av_realloc_f(fourxm->tracks,
                                              sizeof(AudioTrack),
                                              current_track + 1);
                if (!fourxm->tracks) {
                    ret = AVERROR(ENOMEM);
                    goto fail;
                }
                memset(&fourxm->tracks[fourxm->track_count], 0,
                       sizeof(AudioTrack) * (current_track + 1 - fourxm->track_count));
                fourxm->track_count = current_track + 1;
            }
            fourxm->tracks[current_track].adpcm       = AV_RL32(&header[i + 12]);
            fourxm->tracks[current_track].channels    = AV_RL32(&header[i + 36]);
            fourxm->tracks[current_track].sample_rate = AV_RL32(&header[i + 40]);
//.........这里部分代码省略.........

static int flic_read_packet(AVFormatContext *s,
                            AVPacket *pkt)
{
    FlicDemuxContext *flic = s->priv_data;
    ByteIOContext *pb = s->pb;
    int packet_read = 0;
    unsigned int size;
    int magic;
    int ret = 0;
    unsigned char preamble[FLIC_PREAMBLE_SIZE];

    while (!packet_read) {

        if ((ret = get_buffer(pb, preamble, FLIC_PREAMBLE_SIZE)) !=
            FLIC_PREAMBLE_SIZE) {
            ret = AVERROR(EIO);
            break;
        }

        size = AV_RL32(&preamble[0]);
        magic = AV_RL16(&preamble[4]);

        if (((magic == FLIC_CHUNK_MAGIC_1) || (magic == FLIC_CHUNK_MAGIC_2)) && size > FLIC_PREAMBLE_SIZE) {
            if (av_new_packet(pkt, size)) {
                ret = AVERROR(EIO);
                break;
            }
            pkt->stream_index = flic->video_stream_index;
            pkt->pts = flic->frame_number++;
            pkt->pos = url_ftell(pb);
            memcpy(pkt->data, preamble, FLIC_PREAMBLE_SIZE);
            ret = get_buffer(pb, pkt->data + FLIC_PREAMBLE_SIZE,
                size - FLIC_PREAMBLE_SIZE);
            if (ret != size - FLIC_PREAMBLE_SIZE) {
                av_free_packet(pkt);
                ret = AVERROR(EIO);
            }
            packet_read = 1;
        } else if (magic == FLIC_TFTD_CHUNK_AUDIO) {
            if (av_new_packet(pkt, size)) {
                ret = AVERROR(EIO);
                break;
            }

            /* skip useless 10B sub-header (yes, it's not accounted for in the chunk header) */
            url_fseek(pb, 10, SEEK_CUR);

            pkt->stream_index = flic->audio_stream_index;
            pkt->pos = url_ftell(pb);
            ret = get_buffer(pb, pkt->data, size);

            if (ret != size) {
                av_free_packet(pkt);
                ret = AVERROR(EIO);
            }

            packet_read = 1;
        } else {
            /* not interested in this chunk */
            url_fseek(pb, size - 6, SEEK_CUR);
        }
    }

    return ret;
}

static int flic_read_header(AVFormatContext *s,
                            AVFormatParameters *ap)
{
    FlicDemuxContext *flic = s->priv_data;
    ByteIOContext *pb = s->pb;
    unsigned char header[FLIC_HEADER_SIZE];
    AVStream *st, *ast;
    int speed;
    int magic_number;
    unsigned char preamble[FLIC_PREAMBLE_SIZE];

    flic->frame_number = 0;

    /* load the whole header and pull out the width and height */
    if (get_buffer(pb, header, FLIC_HEADER_SIZE) != FLIC_HEADER_SIZE)
        return AVERROR(EIO);

    magic_number = AV_RL16(&header[4]);
    speed = AV_RL32(&header[0x10]);
    if (speed == 0)
        speed = FLIC_DEFAULT_SPEED;

    /* initialize the decoder streams */
    st = av_new_stream(s, 0);
    if (!st)
        return AVERROR(ENOMEM);
    flic->video_stream_index = st->index;
    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
    st->codec->codec_id = CODEC_ID_FLIC;
    st->codec->codec_tag = 0;  /* no fourcc */
    st->codec->width = AV_RL16(&header[0x08]);
    st->codec->height = AV_RL16(&header[0x0A]);

    if (!st->codec->width || !st->codec->height) {
        /* Ugly hack needed for the following sample: */
        /* http://samples.mplayerhq.hu/fli-flc/fli-bugs/specular.flc */
        av_log(s, AV_LOG_WARNING,
               "File with no specified width/height. Trying 640x480.\n");
        st->codec->width  = 640;
        st->codec->height = 480;
    }

    /* send over the whole 128-byte FLIC header */
    st->codec->extradata_size = FLIC_HEADER_SIZE;
    st->codec->extradata = av_malloc(FLIC_HEADER_SIZE);
    memcpy(st->codec->extradata, header, FLIC_HEADER_SIZE);

    /* peek at the preamble to detect TFTD videos - they seem to always start with an audio chunk */
    if (get_buffer(pb, preamble, FLIC_PREAMBLE_SIZE) != FLIC_PREAMBLE_SIZE) {
        av_log(s, AV_LOG_ERROR, "Failed to peek at preamble\n");
        return AVERROR(EIO);
    }

    url_fseek(pb, -FLIC_PREAMBLE_SIZE, SEEK_CUR);

    /* Time to figure out the framerate:
     * If the first preamble's magic number is 0xAAAA then this file is from
     * X-COM: Terror from the Deep. If on the other hand there is a FLIC chunk
     * magic number at offset 0x10 assume this file is from Magic Carpet instead.
     * If neither of the above is true then this is a normal FLIC file.
     */
    if (AV_RL16(&preamble[4]) == FLIC_TFTD_CHUNK_AUDIO) {
        /* TFTD videos have an extra 22050 Hz 8-bit mono audio stream */
        ast = av_new_stream(s, 1);
        if (!ast)
            return AVERROR(ENOMEM);

        flic->audio_stream_index = ast->index;

        /* all audio frames are the same size, so use the size of the first chunk for block_align */
        ast->codec->block_align = AV_RL32(&preamble[0]);
        ast->codec->codec_type = CODEC_TYPE_AUDIO;
        ast->codec->codec_id = CODEC_ID_PCM_U8;
        ast->codec->codec_tag = 0;
        ast->codec->sample_rate = FLIC_TFTD_SAMPLE_RATE;
        ast->codec->channels = 1;
        ast->codec->sample_fmt = SAMPLE_FMT_U8;
        ast->codec->bit_rate = st->codec->sample_rate * 8;
        ast->codec->bits_per_coded_sample = 8;
        ast->codec->channel_layout = CH_LAYOUT_MONO;
        ast->codec->extradata_size = 0;

        /* Since the header information is incorrect we have to figure out the
         * framerate using block_align and the fact that the audio is 22050 Hz.
         * We usually have two cases: 2205 -> 10 fps and 1470 -> 15 fps */
        av_set_pts_info(st, 64, ast->codec->block_align, FLIC_TFTD_SAMPLE_RATE);
        av_set_pts_info(ast, 64, 1, FLIC_TFTD_SAMPLE_RATE);
    } else if (AV_RL16(&header[0x10]) == FLIC_CHUNK_MAGIC_1) {
        av_set_pts_info(st, 64, FLIC_MC_SPEED, 70);

        /* rewind the stream since the first chunk is at offset 12 */
        url_fseek(pb, 12, SEEK_SET);

        /* send over abbreviated FLIC header chunk */
        av_free(st->codec->extradata);
        st->codec->extradata_size = 12;
        st->codec->extradata = av_malloc(12);
        memcpy(st->codec->extradata, header, 12);

    } else if (magic_number == FLIC_FILE_MAGIC_1) {
//.........这里部分代码省略.........

/** Read incoming MMST media, header or command packet. */
static MMSSCPacketType get_tcp_server_response(MMSContext *mms)
{
    int read_result;
    MMSSCPacketType packet_type= -1;

    for(;;) {
        read_result = url_read_complete(mms->mms_hd, mms->in_buffer, 8);
        if (read_result != 8) {
            if(read_result < 0) {
                av_log(NULL, AV_LOG_ERROR,
                       "Error reading packet header: %d (%s)\n",
                       read_result, strerror(read_result));
                packet_type = SC_PKT_CANCEL;
            } else {
                av_log(NULL, AV_LOG_ERROR,
                       "The server closed the connection\n");
                packet_type = SC_PKT_NO_DATA;
            }
            return packet_type;
        }

        // handle command packet.
        if(AV_RL32(mms->in_buffer + 4)==0xb00bface) {
            int length_remaining, hr;

            mms->incoming_flags= mms->in_buffer[3];
            read_result= url_read_complete(mms->mms_hd, mms->in_buffer+8, 4);
            if(read_result != 4) {
                av_log(NULL, AV_LOG_ERROR,
                       "Reading command packet length failed: %d (%s)\n",
                       read_result,
                       read_result < 0 ? strerror(read_result) :
                           "The server closed the connection");
                return read_result < 0 ? read_result : AVERROR_IO;
            }

            length_remaining= AV_RL32(mms->in_buffer+8) + 4;
            dprintf(NULL, "Length remaining is %d\n", length_remaining);
            // read the rest of the packet.
            if (length_remaining < 0
                || length_remaining > sizeof(mms->in_buffer) - 12) {
                av_log(NULL, AV_LOG_ERROR,
                       "Incoming packet length %d exceeds bufsize %zu\n",
                       length_remaining, sizeof(mms->in_buffer) - 12);
                return AVERROR_INVALIDDATA;
            }
            read_result = url_read_complete(mms->mms_hd, mms->in_buffer + 12,
                                            length_remaining) ;
            if (read_result != length_remaining) {
                av_log(NULL, AV_LOG_ERROR,
                       "Reading pkt data (length=%d) failed: %d (%s)\n",
                       length_remaining, read_result,
                       read_result < 0 ? strerror(read_result) :
                           "The server closed the connection");
                return read_result < 0 ? read_result : AVERROR_IO;
            }
            packet_type= AV_RL16(mms->in_buffer+36);
            hr = AV_RL32(mms->in_buffer + 40);
            if (hr) {
                av_log(NULL, AV_LOG_ERROR,
                       "Server sent an error status code: 0x%08x\n", hr);
                return AVERROR_UNKNOWN;
            }
        } else {
            int length_remaining;
            int packet_id_type;
            int tmp;

            // note we cache the first 8 bytes,
            // then fill up the buffer with the others
            tmp                       = AV_RL16(mms->in_buffer + 6);
            length_remaining          = (tmp - 8) & 0xffff;
            mms->incoming_packet_seq  = AV_RL32(mms->in_buffer);
            packet_id_type            = mms->in_buffer[4];
            mms->incoming_flags       = mms->in_buffer[5];

            if (length_remaining < 0
                || length_remaining > sizeof(mms->in_buffer) - 8) {
                av_log(NULL, AV_LOG_ERROR,
                       "Data length %d is invalid or too large (max=%zu)\n",
                       length_remaining, sizeof(mms->in_buffer));
                return AVERROR_INVALIDDATA;
            }
            mms->remaining_in_len    = length_remaining;
            mms->read_in_ptr         = mms->in_buffer;
            read_result= url_read_complete(mms->mms_hd, mms->in_buffer, length_remaining);
            if(read_result != length_remaining) {
                av_log(NULL, AV_LOG_ERROR,
                       "Failed to read packet data of size %d: %d (%s)\n",
                       length_remaining, read_result,
                       read_result < 0 ? strerror(read_result) :
                           "The server closed the connection");
                return read_result < 0 ? read_result : AVERROR_IO;
            }

            // if we successfully read everything.
            if(packet_id_type == mms->header_packet_id) {
                packet_type = SC_PKT_ASF_HEADER;
                // Store the asf header
//.........这里部分代码省略.........

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
    if(wc->flags & WV_FLOAT){
        av_log(ctx, AV_LOG_ERROR, "Floating point data is not supported\n");
        return -1;
    }
    if(wc->flags & WV_HYBRID){
        av_log(ctx, AV_LOG_ERROR, "Hybrid coding mode is not supported\n");
        return -1;
    }

    bpp = ((wc->flags & 3) + 1) << 3;
    chan = 1 + !(wc->flags & WV_MONO);
    rate = wv_rates[(wc->flags >> 23) & 0xF];
    if(rate == -1){
        av_log(ctx, AV_LOG_ERROR, "Unknown sampling rate\n");
        return -1;
    }
    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 != 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 read_packet(AVFormatContext *s, AVPacket *pkt)
{
    BinkDemuxContext *bink = s->priv_data;
    AVIOContext *pb = s->pb;
    int ret;

    if (bink->current_track < 0) {
        int index_entry;
        AVStream *st = s->streams[0]; // stream 0 is video stream with index

        if (bink->video_pts >= st->duration)
            return AVERROR(EIO);

        index_entry = av_index_search_timestamp(st, bink->video_pts,
                                                AVSEEK_FLAG_ANY);
        if (index_entry < 0) {
            av_log(s, AV_LOG_ERROR,
                   "could not find index entry for frame %"PRId64"\n",
                   bink->video_pts);
            return AVERROR(EIO);
        }

        bink->remain_packet_size = st->index_entries[index_entry].size;
        bink->current_track = 0;
    }

    while (bink->current_track < bink->num_audio_tracks) {
        uint32_t audio_size = avio_rl32(pb);
        if (audio_size > bink->remain_packet_size - 4) {
            av_log(s, AV_LOG_ERROR,
                   "frame %"PRId64": audio size in header (%u) > size of packet left (%u)\n",
                   bink->video_pts, audio_size, bink->remain_packet_size);
            return AVERROR(EIO);
        }
        bink->remain_packet_size -= 4 + audio_size;
        bink->current_track++;
        if (audio_size >= 4) {
            /* get one audio packet per track */
            if ((ret = av_get_packet(pb, pkt, audio_size)) < 0)
                return ret;
            pkt->stream_index = bink->current_track;
            pkt->pts = bink->audio_pts[bink->current_track - 1];

            /* Each audio packet reports the number of decompressed samples
               (in bytes). We use this value to calcuate the audio PTS */
            if (pkt->size >= 4)
                bink->audio_pts[bink->current_track -1] +=
                    AV_RL32(pkt->data) / (2 * s->streams[bink->current_track]->codec->channels);
            return 0;
        } else {
            avio_skip(pb, audio_size);
        }
    }

    /* get video packet */
    if ((ret = av_get_packet(pb, pkt, bink->remain_packet_size)) < 0)
        return ret;
    pkt->stream_index = 0;
    pkt->pts = bink->video_pts++;
    pkt->flags |= AV_PKT_FLAG_KEY;

    /* -1 instructs the next call to read_packet() to read the next frame */
    bink->current_track = -1;

    return 0;
}

static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
                        AVPacket *avpkt)
{
    JvContext *s = avctx->priv_data;
    int buf_size = avpkt->size;
    const uint8_t *buf = avpkt->data;
    const uint8_t *buf_end = buf + buf_size;
    int video_size, video_type, i, j, ret;

    video_size = AV_RL32(buf);
    video_type = buf[4];
    buf += 5;

    if (video_size) {
        if ((ret = ff_reget_buffer(avctx, s->frame)) < 0) {
            av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
            return ret;
        }

        if (video_type == 0 || video_type == 1) {
            GetBitContext gb;
            init_get_bits(&gb, buf, 8 * FFMIN(video_size, buf_end - buf));

            for (j = 0; j < avctx->height; j += 8)
                for (i = 0; i < avctx->width; i += 8)
                    decode8x8(&gb,
                              s->frame->data[0] + j * s->frame->linesize[0] + i,
                              s->frame->linesize[0], &s->bdsp);

            buf += video_size;
        } else if (video_type == 2) {
            if (buf + 1 <= buf_end) {
                int v = *buf++;
                for (j = 0; j < avctx->height; j++)
                    memset(s->frame->data[0] + j * s->frame->linesize[0],
                           v, avctx->width);
            }
        } else {
            av_log(avctx, AV_LOG_WARNING,
                   "unsupported frame type %i\n", video_type);
            return AVERROR_INVALIDDATA;
        }
    }

    if (buf < buf_end) {
        for (i = 0; i < AVPALETTE_COUNT && buf + 3 <= buf_end; i++) {
            s->palette[i] = AV_RB24(buf) << 2;
            buf += 3;
        }
        s->palette_has_changed = 1;
    }

    if (video_size) {
        s->frame->key_frame           = 1;
        s->frame->pict_type           = AV_PICTURE_TYPE_I;
        s->frame->palette_has_changed = s->palette_has_changed;
        s->palette_has_changed        = 0;
        memcpy(s->frame->data[1], s->palette, AVPALETTE_SIZE);

        if ((ret = av_frame_ref(data, s->frame)) < 0)
            return ret;
        *got_frame = 1;
    }

    return buf_size;
}

static int write_packet(AVFormatContext *s, AVPacket *pkt)
{
    VideoData *img = s->priv_data;
    AVIOContext *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 number %d from pattern '%s'\n",
                   img->img_number, img->path);