static int vc1_decode_frame(AVCodecContext *avctx, void *data,
                            int *data_size, AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size, n_slices = 0, i;
    VC1Context *v = avctx->priv_data;
    MpegEncContext *s = &v->s;
    AVFrame *pict = data;
    uint8_t *buf2 = NULL;
    const uint8_t *buf_start = buf, *buf_start_second_field = NULL;
    int mb_height, n_slices1=-1;
    struct {
        uint8_t *buf;
        GetBitContext gb;
        int mby_start;
    } *slices = NULL, *tmp;
    v->second_field = 0;
    if(s->flags & CODEC_FLAG_LOW_DELAY)
        s->low_delay = 1;
    
    if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == VC1_CODE_ENDOFSEQ)) {
        
        if (s->low_delay == 0 && s->next_picture_ptr) {
            *pict = s->next_picture_ptr->f;
            s->next_picture_ptr = NULL;
            *data_size = sizeof(AVFrame);
        return buf_size;
    if (s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU) {
        if (v->profile < PROFILE_ADVANCED)
            avctx->pix_fmt = AV_PIX_FMT_VDPAU_WMV3;
        else
            avctx->pix_fmt = AV_PIX_FMT_VDPAU_VC1;
    
    if (avctx->codec_id == AV_CODEC_ID_VC1 || avctx->codec_id == AV_CODEC_ID_VC1IMAGE) {
        int buf_size2 = 0;
        buf2 = av_mallocz(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
        if (IS_MARKER(AV_RB32(buf))) { 
            const uint8_t *start, *end, *next;
            int size;
            next = buf;
            for (start = buf, end = buf + buf_size; next < end; start = next) {
                next = find_next_marker(start + 4, end);
                size = next - start - 4;
                if (size <= 0) continue;
                switch (AV_RB32(start)) {
                case VC1_CODE_FRAME:
                    if (avctx->hwaccel ||
                        s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU)
                        buf_start = start;
                    buf_size2 = vc1_unescape_buffer(start + 4, size, buf2);
                    break;
                case VC1_CODE_FIELD: {
                    int buf_size3;
                    if (avctx->hwaccel ||
                        s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU)
                        buf_start_second_field = start;
                    tmp = av_realloc(slices, sizeof(*slices) * (n_slices+1));
                    if (!tmp)
                    slices = tmp;
                    slices[n_slices].buf = av_mallocz(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
                    if (!slices[n_slices].buf)
                    buf_size3 = vc1_unescape_buffer(start + 4, size,
                                                    slices[n_slices].buf);
                    init_get_bits(&slices[n_slices].gb, slices[n_slices].buf,
                                  buf_size3 << 3);
                    

                    slices[n_slices].mby_start = s->mb_height >> 1;
                    n_slices1 = n_slices - 1; 
                    n_slices++;
                    break;
                case VC1_CODE_ENTRYPOINT: 
                    buf_size2 = vc1_unescape_buffer(start + 4, size, buf2);
                    init_get_bits(&s->gb, buf2, buf_size2 * 8);
                    ff_vc1_decode_entry_point(avctx, v, &s->gb);
                    break;
                case VC1_CODE_SLICE: {
                    int buf_size3;
                    tmp = av_realloc(slices, sizeof(*slices) * (n_slices+1));
                    if (!tmp)
                    slices = tmp;
                    slices[n_slices].buf = av_mallocz(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
                    if (!slices[n_slices].buf)
                    buf_size3 = vc1_unescape_buffer(start + 4, size,
                                                    slices[n_slices].buf);
                    init_get_bits(&slices[n_slices].gb, slices[n_slices].buf,
                                  buf_size3 << 3);
                    slices[n_slices].mby_start = get_bits(&slices[n_slices].gb, 9);
                    n_slices++;
                    break;
        } else if (v->interlace && ((buf[0] & 0xC0) == 0xC0)) { 
            const uint8_t *divider;
            int buf_size3;
            divider = find_next_marker(buf, buf + buf_size);
            if ((divider == (buf + buf_size)) || AV_RB32(divider) != VC1_CODE_FIELD) {
                av_log(avctx, AV_LOG_ERROR, "Error in WVC1 interlaced frame\n");
            } else { 
                if (avctx->hwaccel ||
                    s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU)
                    buf_start_second_field = divider;
                tmp = av_realloc(slices, sizeof(*slices) * (n_slices+1));
                if (!tmp)
                slices = tmp;
                slices[n_slices].buf = av_mallocz(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
                if (!slices[n_slices].buf)
                buf_size3 = vc1_unescape_buffer(divider + 4, buf + buf_size - divider - 4, slices[n_slices].buf);
                init_get_bits(&slices[n_slices].gb, slices[n_slices].buf,
                              buf_size3 << 3);
                slices[n_slices].mby_start = s->mb_height >> 1;
                n_slices1 = n_slices - 1;
                n_slices++;
            buf_size2 = vc1_unescape_buffer(buf, divider - buf, buf2);
        } else {
            buf_size2 = vc1_unescape_buffer(buf, buf_size, buf2);
        init_get_bits(&s->gb, buf2, buf_size2*8);
    } else
        init_get_bits(&s->gb, buf, buf_size*8);
    if (v->res_sprite) {
        v->new_sprite  = !get_bits1(&s->gb);
        v->two_sprites =  get_bits1(&s->gb);
        



        if (avctx->codec_id == AV_CODEC_ID_WMV3IMAGE || avctx->codec_id == AV_CODEC_ID_VC1IMAGE) {
            if (v->new_sprite) {
                
                avctx->width  = avctx->coded_width  = v->sprite_width;
                avctx->height = avctx->coded_height = v->sprite_height;
            } else {
                goto image;
    if (s->context_initialized &&
        (s->width  != avctx->coded_width ||
         s->height != avctx->coded_height)) {
        ff_vc1_decode_end(avctx);
    if (!s->context_initialized) {
        if (ff_msmpeg4_decode_init(avctx) < 0 || ff_vc1_decode_init_alloc_tables(v) < 0)
        s->low_delay = !avctx->has_b_frames || v->res_sprite;
        if (v->profile == PROFILE_ADVANCED) {
            s->h_edge_pos = avctx->coded_width;
            s->v_edge_pos = avctx->coded_height;
    

    if (s->current_picture_ptr == NULL || s->current_picture_ptr->f.data[0]) {
        int i = ff_find_unused_picture(s, 0);
        if (i < 0)
        s->current_picture_ptr = &s->picture[i];
    
    v->pic_header_flag = 0;
    if (v->profile < PROFILE_ADVANCED) {
        if (ff_vc1_parse_frame_header(v, &s->gb) < 0) {
    } else {
        if (ff_vc1_parse_frame_header_adv(v, &s->gb) < 0) {
    if (avctx->debug & FF_DEBUG_PICT_INFO)
        av_log(v->s.avctx, AV_LOG_DEBUG, "pict_type: %c\n", av_get_picture_type_char(s->pict_type));
    if ((avctx->codec_id == AV_CODEC_ID_WMV3IMAGE || avctx->codec_id == AV_CODEC_ID_VC1IMAGE)
        && s->pict_type != AV_PICTURE_TYPE_I) {
        av_log(v->s.avctx, AV_LOG_ERROR, "Sprite decoder: expected I-frame\n");
    
    s->current_picture_ptr->f.repeat_pict = 0;
    
    
    if (v->rff) {
        
        s->current_picture_ptr->f.repeat_pict = 1;
    } else if (v->rptfrm) {
        
        s->current_picture_ptr->f.repeat_pict = v->rptfrm * 2;
    
    s->current_picture.f.pict_type = s->pict_type;
    s->current_picture.f.key_frame = s->pict_type == AV_PICTURE_TYPE_I;
    
    if (s->last_picture_ptr == NULL && (s->pict_type == AV_PICTURE_TYPE_B || s->dropable)) {
    if ((avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type == AV_PICTURE_TYPE_B) ||
        (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type != AV_PICTURE_TYPE_I) ||
         avctx->skip_frame >= AVDISCARD_ALL) {
        goto end;
    if (s->next_p_frame_damaged) {
        if (s->pict_type == AV_PICTURE_TYPE_B)
            goto end;
        else
            s->next_p_frame_damaged = 0;
    if (ff_MPV_frame_start(s, avctx) < 0) {
    v->s.current_picture_ptr->f.interlaced_frame = (v->fcm != PROGRESSIVE);
    v->s.current_picture_ptr->f.top_field_first  = v->tff;
    s->me.qpel_put = s->dsp.put_qpel_pixels_tab;
    s->me.qpel_avg = s->dsp.avg_qpel_pixels_tab;
    if ((CONFIG_VC1_VDPAU_DECODER)
        &&s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU)
        ff_vdpau_vc1_decode_picture(s, buf_start, (buf + buf_size) - buf_start);
    else if (avctx->hwaccel) {
        if (v->field_mode && buf_start_second_field) {
            
            s->picture_structure = PICT_BOTTOM_FIELD - v->tff;
            if (avctx->hwaccel->start_frame(avctx, buf_start, buf_start_second_field - buf_start) < 0)
            if (avctx->hwaccel->decode_slice(avctx, buf_start, buf_start_second_field - buf_start) < 0)
            if (avctx->hwaccel->end_frame(avctx) < 0)
            
            s->gb = slices[n_slices1 + 1].gb;
            s->picture_structure = PICT_TOP_FIELD + v->tff;
            v->second_field = 1;
            v->pic_header_flag = 0;
            if (ff_vc1_parse_frame_header_adv(v, &s->gb) < 0) {
                av_log(avctx, AV_LOG_ERROR, "parsing header for second field failed");
            v->s.current_picture_ptr->f.pict_type = v->s.pict_type;
            if (avctx->hwaccel->start_frame(avctx, buf_start_second_field, (buf + buf_size) - buf_start_second_field) < 0)
            if (avctx->hwaccel->decode_slice(avctx, buf_start_second_field, (buf + buf_size) - buf_start_second_field) < 0)
            if (avctx->hwaccel->end_frame(avctx) < 0)
        } else {
            s->picture_structure = PICT_FRAME;
            if (avctx->hwaccel->start_frame(avctx, buf_start, (buf + buf_size) - buf_start) < 0)
            if (avctx->hwaccel->decode_slice(avctx, buf_start, (buf + buf_size) - buf_start) < 0)
            if (avctx->hwaccel->end_frame(avctx) < 0)
    } else {
        if (v->fcm == ILACE_FRAME && s->pict_type == AV_PICTURE_TYPE_B)
            goto err; 
        ff_er_frame_start(s);
        v->bits = buf_size * 8;
        v->end_mb_x = s->mb_width;
        if (v->field_mode) {
            uint8_t *tmp[2];
            s->current_picture.f.linesize[0] <<= 1;
            s->current_picture.f.linesize[1] <<= 1;
            s->current_picture.f.linesize[2] <<= 1;
            s->linesize                      <<= 1;
            s->uvlinesize                    <<= 1;
            tmp[0]          = v->mv_f_last[0];
            tmp[1]          = v->mv_f_last[1];
            v->mv_f_last[0] = v->mv_f_next[0];
            v->mv_f_last[1] = v->mv_f_next[1];
            v->mv_f_next[0] = v->mv_f[0];
            v->mv_f_next[1] = v->mv_f[1];
            v->mv_f[0] = tmp[0];
            v->mv_f[1] = tmp[1];
        mb_height = s->mb_height >> v->field_mode;
        for (i = 0; i <= n_slices; i++) {
            if (i > 0 &&  slices[i - 1].mby_start >= mb_height) {
                if (v->field_mode <= 0) {
                    av_log(v->s.avctx, AV_LOG_ERROR, "Slice %d starts beyond "
                           "picture boundary (%d >= %d)\n", i,
                           slices[i - 1].mby_start, mb_height);
                    continue;
                v->second_field = 1;
                v->blocks_off   = s->mb_width  * s->mb_height << 1;
                v->mb_off       = s->mb_stride * s->mb_height >> 1;
            } else {
                v->second_field = 0;
                v->blocks_off   = 0;
                v->mb_off       = 0;
            if (i) {
                v->pic_header_flag = 0;
                if (v->field_mode && i == n_slices1 + 2) {
                    if (ff_vc1_parse_frame_header_adv(v, &s->gb) < 0) {
                        av_log(v->s.avctx, AV_LOG_ERROR, "Field header damaged\n");
                        continue;
                } else if (get_bits1(&s->gb)) {
                    v->pic_header_flag = 1;
                    if (ff_vc1_parse_frame_header_adv(v, &s->gb) < 0) {
                        av_log(v->s.avctx, AV_LOG_ERROR, "Slice header damaged\n");
                        continue;
            s->start_mb_y = (i == 0) ? 0 : FFMAX(0, slices[i-1].mby_start % mb_height);
            if (!v->field_mode || v->second_field)
                s->end_mb_y = (i == n_slices     ) ? mb_height : FFMIN(mb_height, slices[i].mby_start % mb_height);
            else
                s->end_mb_y = (i <= n_slices1 + 1) ? mb_height : FFMIN(mb_height, slices[i].mby_start % mb_height);
            if (s->end_mb_y <= s->start_mb_y) {
                av_log(v->s.avctx, AV_LOG_ERROR, "end mb y %d %d invalid\n", s->end_mb_y, s->start_mb_y);
                continue;
            ff_vc1_decode_blocks(v);
            if (i != n_slices)
                s->gb = slices[i].gb;
        if (v->field_mode) {
            v->second_field = 0;
            if (s->pict_type == AV_PICTURE_TYPE_B) {
                memcpy(v->mv_f_base, v->mv_f_next_base,
                       2 * (s->b8_stride * (s->mb_height * 2 + 1) + s->mb_stride * (s->mb_height + 1) * 2));
            s->current_picture.f.linesize[0] >>= 1;
            s->current_picture.f.linesize[1] >>= 1;
            s->current_picture.f.linesize[2] >>= 1;
            s->linesize                      >>= 1;
            s->uvlinesize                    >>= 1;
        av_dlog(s->avctx, "Consumed %i/%i bits\n",
                get_bits_count(&s->gb), s->gb.size_in_bits);


        if(s->error_occurred && s->pict_type == AV_PICTURE_TYPE_B)
        if(!v->field_mode)
            ff_er_frame_end(s);
    ff_MPV_frame_end(s);
    if (avctx->codec_id == AV_CODEC_ID_WMV3IMAGE || avctx->codec_id == AV_CODEC_ID_VC1IMAGE) {
image:
        avctx->width  = avctx->coded_width  = v->output_width;
        avctx->height = avctx->coded_height = v->output_height;
        if (avctx->skip_frame >= AVDISCARD_NONREF)
            goto end;
#if CONFIG_WMV3IMAGE_DECODER || CONFIG_VC1IMAGE_DECODER
        if (vc1_decode_sprites(v, &s->gb))
#endif
        *pict      = v->sprite_output_frame;
        *data_size = sizeof(AVFrame);
    } else {
        if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
            *pict = s->current_picture_ptr->f;
        } else if (s->last_picture_ptr != NULL) {
            *pict = s->last_picture_ptr->f;
        if (s->last_picture_ptr || s->low_delay) {
            *data_size = sizeof(AVFrame);
            ff_print_debug_info(s, pict);
end:
    av_free(buf2);
    for (i = 0; i < n_slices; i++)
        av_free(slices[i].buf);
    av_free(slices);
    return buf_size;
err:
    av_free(buf2);
    for (i = 0; i < n_slices; i++)
        av_free(slices[i].buf);
    av_free(slices);
    return -1;