C++ decoder_NewPicture函数代码示例

bool gst_vlc_picture_plane_allocator_hold(
    GstVlcPicturePlaneAllocator *p_allocator, GstBuffer *p_buffer )
{
    picture_t* p_pic = NULL;
    decoder_t* p_dec = p_allocator->p_dec;
    GstVlcPicturePlane *p_mem;
    int i_plane;

    if( !decoder_UpdateVideoFormat( p_dec ) )
        p_pic = decoder_NewPicture( p_dec );
    if( !p_pic )
    {
        msg_Err( p_allocator->p_dec, "failed to acquire picture from vout" );
        return false;
    }

    for( i_plane = 0; i_plane < p_pic->i_planes; i_plane++ )
    {
        p_mem = (GstVlcPicturePlane*) gst_buffer_peek_memory ( p_buffer,
                i_plane );
        p_mem->p_pic = p_pic;
        p_mem->p_plane = &p_pic->p[ i_plane ];
    }

    return true;
}

/****************************************************************************
 * DecodeBlock: the whole thing
 ****************************************************************************
 * This function must be fed with a complete compressed frame.
 ****************************************************************************/
static picture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    block_t *p_block;

    if( !pp_block || !*pp_block ) return NULL;

    p_block = *pp_block;

    // create new picture
    if( p_sys->p_pic != NULL )
        picture_Release( p_sys->p_pic );
    p_sys->p_pic = decoder_NewPicture( p_dec );
    p_sys->p_pic->b_force = true;
    p_sys->p_pic->p->i_pitch = p_dec->p_sys->i_pitch;
    p_sys->p_pic->date = p_block->i_pts > 0 ? p_block->i_pts : p_block->i_dts;

    // lock input and copy to picture
    p_sys->p_pic->p->p_pixels = p_sys->pf_lock( p_dec->p_sys->p_data );

    // unlock input
    p_sys->pf_unlock( p_dec->p_sys->p_data );

    block_Release( *pp_block ); *pp_block = NULL;
    return p_sys->p_pic;
}

/*****************************************************************************
 * DecodePacket: decodes a Theora packet.
 *****************************************************************************/
static picture_t *DecodePacket( decoder_t *p_dec, ogg_packet *p_oggpacket )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    picture_t *p_pic;
    yuv_buffer yuv;

    theora_decode_packetin( &p_sys->td, p_oggpacket );

    /* Check for keyframe */
    if( !(p_oggpacket->packet[0] & 0x80) /* data packet */ &&
        !(p_oggpacket->packet[0] & 0x40) /* intra frame */ )
        p_sys->b_decoded_first_keyframe = true;

    /* If we haven't seen a single keyframe yet, don't let Theora decode
     * anything, otherwise we'll get display artifacts.  (This is impossible
     * in the general case, but can happen if e.g. we play a network stream
     * using a timed URL, such that the server doesn't start the video with a
     * keyframe). */
    if( p_sys->b_decoded_first_keyframe )
        theora_decode_YUVout( &p_sys->td, &yuv );
    else
        return NULL;

    /* Get a new picture */
    p_pic = decoder_NewPicture( p_dec );
    if( !p_pic ) return NULL;

    theora_CopyPicture( p_pic, &yuv );

    p_pic->date = p_sys->i_pts;

    return p_pic;
}

/****************************************************************************
 * DecodeBlock: the whole thing
 ****************************************************************************/
static picture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
{
    decoder_sys_t *p_sys = (decoder_sys_t*) p_dec->p_sys;
    picture_t *p_pic;

    if( pp_block == NULL || !*pp_block ) return NULL;
    p_pic = decoder_NewPicture( p_dec );
    if( p_pic == NULL )
    {
        msg_Err( p_dec, "cannot get picture" );
        goto error;
    }

    if( p_sys->b_reload && (mdate() >= p_sys->i_next) )
    {
        var_TriggerCallback( p_dec, "fake-file" );
        /* next period */
        p_sys->i_next = (mtime_t)(p_sys->i_reload + mdate());
    }
    vlc_mutex_lock( &p_dec->p_sys->lock );
    picture_Copy( p_pic, p_dec->p_sys->p_image );
    vlc_mutex_unlock( &p_dec->p_sys->lock );

    p_pic->date = (*pp_block)->i_pts;

error:
    block_Release( *pp_block );
    *pp_block = NULL;

    return p_pic;
}

/*****************************************************************************
 * DecodeFrame: decodes a video frame.
 *****************************************************************************/
static picture_t *DecodeFrame( decoder_t *p_dec, block_t *p_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    picture_t *p_pic;

    /* Get a new picture */
    p_pic = decoder_NewPicture( p_dec );
    if( !p_pic )
    {
        block_Release( p_block );
        return NULL;
    }

    FillPicture( p_dec, p_block, p_pic );

    p_pic->date = date_Get( &p_sys->pts );
    if( p_block->i_flags & BLOCK_FLAG_INTERLACED_MASK )
    {
        p_pic->b_progressive = false;
        p_pic->i_nb_fields = 2;
        if( p_block->i_flags & BLOCK_FLAG_TOP_FIELD_FIRST )
            p_pic->b_top_field_first = true;
        else
            p_pic->b_top_field_first = false;
    }
    else
        p_pic->b_progressive = true;

    block_Release( p_block );
    return p_pic;
}

/* Returns a new picture buffer */
static inline picture_t *ffmpeg_NewPictBuf( decoder_t *p_dec,
                                            AVCodecContext *p_context )
{
    decoder_sys_t *p_sys = p_dec->p_sys;

    p_dec->fmt_out.video.i_width = p_context->width;
    p_dec->fmt_out.video.i_height = p_context->height;

    if( !p_context->width || !p_context->height )
    {
        return NULL; /* invalid display size */
    }

    if( !p_sys->p_va && GetVlcChroma( &p_dec->fmt_out.video, p_context->pix_fmt ) )
    {
        /* we are doomed, but not really, because most codecs set their pix_fmt
         * much later
         * FIXME does it make sense here ? */
        p_dec->fmt_out.video.i_chroma = VLC_CODEC_I420;
    }
    p_dec->fmt_out.i_codec = p_dec->fmt_out.video.i_chroma;

    /* If an aspect-ratio was specified in the input format then force it */
    if( p_dec->fmt_in.video.i_aspect )
    {
        p_dec->fmt_out.video.i_aspect = p_dec->fmt_in.video.i_aspect;
    }
    else
    {
        p_dec->fmt_out.video.i_aspect =
            VOUT_ASPECT_FACTOR * ( av_q2d(p_context->sample_aspect_ratio) *
                p_context->width / p_context->height );
        p_dec->fmt_out.video.i_sar_num = p_context->sample_aspect_ratio.num;
        p_dec->fmt_out.video.i_sar_den = p_context->sample_aspect_ratio.den;

        if( p_dec->fmt_out.video.i_aspect == 0 )
        {
            p_dec->fmt_out.video.i_aspect =
                VOUT_ASPECT_FACTOR * p_context->width / p_context->height;
        }
    }

    if( p_dec->fmt_in.video.i_frame_rate > 0 &&
        p_dec->fmt_in.video.i_frame_rate_base > 0 )
    {
        p_dec->fmt_out.video.i_frame_rate =
            p_dec->fmt_in.video.i_frame_rate;
        p_dec->fmt_out.video.i_frame_rate_base =
            p_dec->fmt_in.video.i_frame_rate_base;
    }
    else if( p_context->time_base.num > 0 && p_context->time_base.den > 0 )
    {
        p_dec->fmt_out.video.i_frame_rate = p_context->time_base.den;
        p_dec->fmt_out.video.i_frame_rate_base = p_context->time_base.num;
    }

    return decoder_NewPicture( p_dec );
}

/* Returns a new picture buffer */
static inline picture_t *ffmpeg_NewPictBuf( decoder_t *p_dec,
                                            AVCodecContext *p_context )
{
    bool hwaccel = p_dec->p_sys->p_va != NULL;

    if (lavc_UpdateVideoFormat(p_dec, p_context, hwaccel))
        return NULL;
    return decoder_NewPicture( p_dec );
}

/*****************************************************************************
 * GetNewPicture: Get a new picture from the vout and set the buf struct
 *****************************************************************************/
static picture_t *GetNewPicture( decoder_t *p_dec )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    picture_t *p_pic;

    p_dec->fmt_out.video.i_width = p_sys->p_info->sequence->width;
    p_dec->fmt_out.video.i_visible_width =
        p_sys->p_info->sequence->picture_width;
    p_dec->fmt_out.video.i_height = p_sys->p_info->sequence->height;
    p_dec->fmt_out.video.i_visible_height =
        p_sys->p_info->sequence->picture_height;
    p_dec->fmt_out.video.i_sar_num = p_sys->i_sar_num;
    p_dec->fmt_out.video.i_sar_den = p_sys->i_sar_den;

    if( p_sys->p_info->sequence->frame_period > 0 )
    {
        p_dec->fmt_out.video.i_frame_rate =
            (uint32_t)( (uint64_t)1001000000 * 27 /
                        p_sys->p_info->sequence->frame_period );
        p_dec->fmt_out.video.i_frame_rate_base = 1001;
    }

    p_dec->fmt_out.i_codec =
        ( p_sys->p_info->sequence->chroma_height <
          p_sys->p_info->sequence->height ) ?
        VLC_CODEC_I420 : VLC_CODEC_I422;

    /* Get a new picture */
    if( decoder_UpdateVideoFormat( p_dec ) )
        return NULL;
    p_pic = decoder_NewPicture( p_dec );

    if( p_pic == NULL )
        return NULL;

    p_pic->b_progressive = p_sys->p_info->current_picture != NULL ?
        p_sys->p_info->current_picture->flags & PIC_FLAG_PROGRESSIVE_FRAME : 1;
    p_pic->b_top_field_first = p_sys->p_info->current_picture != NULL ?
        p_sys->p_info->current_picture->flags & PIC_FLAG_TOP_FIELD_FIRST : 1;
    p_pic->i_nb_fields = p_sys->p_info->current_picture != NULL ?
        p_sys->p_info->current_picture->nb_fields : 2;

    return p_pic;
}

/*****************************************************************************
 * DecodeFrame: decodes a video frame.
 *****************************************************************************/
static int DecodeFrame( decoder_t *p_dec, block_t *p_block )
{
    if( p_block == NULL ) /* No Drain */
        return VLCDEC_SUCCESS;

    p_block = DecodeBlock( p_dec, p_block );
    if( p_block == NULL )
        return VLCDEC_SUCCESS;

    decoder_sys_t *p_sys = p_dec->p_sys;

    /* Get a new picture */
    picture_t *p_pic = NULL;
    if( !decoder_UpdateVideoFormat( p_dec ) )
        p_pic = decoder_NewPicture( p_dec );
    if( p_pic == NULL )
    {
        block_Release( p_block );
        return VLCDEC_SUCCESS;
    }

    FillPicture( p_dec, p_block, p_pic );

    /* Date management: 1 frame per packet */
    p_pic->date = date_Get( &p_dec->p_sys->pts );
    date_Increment( &p_sys->pts, 1 );

    if( p_block->i_flags & BLOCK_FLAG_INTERLACED_MASK )
    {
        p_pic->b_progressive = false;
        p_pic->i_nb_fields = (p_block->i_flags & BLOCK_FLAG_SINGLE_FIELD) ? 1 : 2;
        if( p_block->i_flags & BLOCK_FLAG_TOP_FIELD_FIRST )
            p_pic->b_top_field_first = true;
        else
            p_pic->b_top_field_first = false;
    }
    else
        p_pic->b_progressive = true;

    block_Release( p_block );
    decoder_QueueVideo( p_dec, p_pic );
    return VLCDEC_SUCCESS;
}

/*****************************************************************************
 * DecodePacket: decodes a Theora packet.
 *****************************************************************************/
static picture_t *DecodePacket( decoder_t *p_dec, ogg_packet *p_oggpacket )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    picture_t *p_pic;
    th_ycbcr_buffer ycbcr;

    /* TODO: Implement _granpos (3rd parameter here) and add the
     * call to TH_DECCTL_SET_GRANDPOS after seek */
    /* TODO: If the return is TH_DUPFRAME, we don't need to display a new
     * frame, but we do need to keep displaying the previous one. */
    if (th_decode_packetin( p_sys->tcx, p_oggpacket, NULL ) < 0)
        return NULL; /* bad packet */

    /* Check for keyframe */
    if( !(p_oggpacket->packet[0] & 0x80) /* data packet */ &&
        !(p_oggpacket->packet[0] & 0x40) /* intra frame */ )
        p_sys->b_decoded_first_keyframe = true;

    /* If we haven't seen a single keyframe yet, don't let Theora decode
     * anything, otherwise we'll get display artifacts.  (This is impossible
     * in the general case, but can happen if e.g. we play a network stream
     * using a timed URL, such that the server doesn't start the video with a
     * keyframe). */
    if( !p_sys->b_decoded_first_keyframe )
        return NULL; /* Wait until we've decoded the first keyframe */

    if( th_decode_ycbcr_out( p_sys->tcx, ycbcr ) ) /* returns 0 on success */
        return NULL;

    /* Get a new picture */
    if( decoder_UpdateVideoFormat( p_dec ) )
        return NULL;
    p_pic = decoder_NewPicture( p_dec );
    if( !p_pic ) return NULL;

    theora_CopyPicture( p_pic, ycbcr );

    p_pic->date = p_sys->i_pts;
    p_pic->b_progressive = true;

    return p_pic;
}

/*****************************************************************************
 * DecodePacket: decodes a Daala packet.
 *****************************************************************************/
static picture_t *DecodePacket( decoder_t *p_dec, ogg_packet *p_oggpacket )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    picture_t *p_pic;
    od_img ycbcr;

    if (daala_decode_packet_in( p_sys->dcx, &ycbcr, p_oggpacket ) < 0)
        return NULL; /* bad packet */

    /* Check for keyframe */
    if( daala_packet_iskeyframe( p_oggpacket->packet, p_oggpacket->bytes ) )
        p_sys->b_decoded_first_keyframe = true;

    /* Get a new picture */
    p_pic = decoder_NewPicture( p_dec );
    if( !p_pic ) return NULL;

    daala_CopyPicture( p_pic, &ycbcr );

    p_pic->date = p_sys->i_pts;

    return p_pic;
}

static BC_STATUS ourCallback(void *shnd, uint32_t width, uint32_t height, uint32_t stride, void *pOut)
{
    VLC_UNUSED(width); VLC_UNUSED(height); VLC_UNUSED(stride);

    decoder_t *p_dec          = (decoder_t *)shnd;
    BC_DTS_PROC_OUT *proc_out = p_dec->p_sys->proc_out;
    BC_DTS_PROC_OUT *proc_in  = (BC_DTS_PROC_OUT*)pOut;

    /* Direct Rendering */
    /* Do not allocate for the second-field in the pair, in interlaced */
    if( !(proc_in->PicInfo.flags & VDEC_FLAG_INTERLACED_SRC) ||
        !(proc_in->PicInfo.flags & VDEC_FLAG_FIELDPAIR) )
        p_dec->p_sys->p_pic = decoder_NewPicture( p_dec );

    /* */
    picture_t *p_pic = p_dec->p_sys->p_pic;
    if( !p_pic )
        return BC_STS_ERROR;

    /* Interlacing */
    p_pic->b_progressive     = !(proc_in->PicInfo.flags & VDEC_FLAG_INTERLACED_SRC);
    p_pic->b_top_field_first = !(proc_in->PicInfo.flags & VDEC_FLAG_BOTTOM_FIRST);
    p_pic->i_nb_fields       = p_pic->b_progressive? 1: 2;

    /* Filling out the struct */
    proc_out->Ybuff      = !(proc_in->PicInfo.flags & VDEC_FLAG_FIELDPAIR) ?
                             &p_pic->p[0].p_pixels[0] :
                             &p_pic->p[0].p_pixels[p_pic->p[0].i_pitch];
    proc_out->YbuffSz    = 2 * p_pic->p[0].i_pitch;
    proc_out->StrideSz   = (proc_in->PicInfo.flags & VDEC_FLAG_INTERLACED_SRC)?
                            2 * (p_pic->p[0].i_pitch/2) - p_dec->fmt_out.video.i_width:
                            p_pic->p[0].i_pitch/2 - p_dec->fmt_out.video.i_width;
    proc_out->PoutFlags |= BC_POUT_FLAGS_STRIDE;              /* Trust Stride info */

    return BC_STS_SUCCESS;
}

/****************************************************************************
 * DecodeBlock: the whole thing
 ****************************************************************************
 * This function must be fed with a complete compressed frame.
 ****************************************************************************/
static picture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    block_t *p_block;
    picture_t *p_pic = 0;

    png_uint_32 i_width, i_height;
    int i_color_type, i_interlace_type, i_compression_type, i_filter_type;
    int i_bit_depth, i;

    png_structp p_png;
    png_infop p_info, p_end_info;
    png_bytep *p_row_pointers = NULL;

    if( !pp_block || !*pp_block ) return NULL;

    p_block = *pp_block;
    p_sys->b_error = false;

    if( p_block->i_flags & BLOCK_FLAG_DISCONTINUITY )
    {
        block_Release( p_block ); *pp_block = NULL;
        return NULL;
    }

    p_png = png_create_read_struct( PNG_LIBPNG_VER_STRING, 0, 0, 0 );
    if( p_png == NULL )
    {
        block_Release( p_block ); *pp_block = NULL;
        return NULL;
    }

    p_info = png_create_info_struct( p_png );
    if( p_info == NULL )
    {
        png_destroy_read_struct( &p_png, NULL, NULL );
        block_Release( p_block ); *pp_block = NULL;
        return NULL;
    }

    p_end_info = png_create_info_struct( p_png );
    if( p_end_info == NULL )
    {
        png_destroy_read_struct( &p_png, &p_info, NULL );
        block_Release( p_block ); *pp_block = NULL;
        return NULL;
    }

    /* libpng longjmp's there in case of error */
    if( setjmp( png_jmpbuf( p_png ) ) )
        goto error;

    png_set_read_fn( p_png, (void *)p_block, user_read );
    png_set_error_fn( p_png, (void *)p_dec, user_error, user_warning );

    png_read_info( p_png, p_info );
    if( p_sys->b_error ) goto error;

    png_get_IHDR( p_png, p_info, &i_width, &i_height,
                  &i_bit_depth, &i_color_type, &i_interlace_type,
                  &i_compression_type, &i_filter_type);
    if( p_sys->b_error ) goto error;

    /* Set output properties */
    p_dec->fmt_out.i_codec = VLC_CODEC_RGBA;
    p_dec->fmt_out.video.i_visible_width = p_dec->fmt_out.video.i_width = i_width;
    p_dec->fmt_out.video.i_visible_height = p_dec->fmt_out.video.i_height = i_height;
    p_dec->fmt_out.video.i_sar_num = 1;
    p_dec->fmt_out.video.i_sar_den = 1;
    p_dec->fmt_out.video.i_rmask = 0x000000ff;
    p_dec->fmt_out.video.i_gmask = 0x0000ff00;
    p_dec->fmt_out.video.i_bmask = 0x00ff0000;

    if( i_color_type == PNG_COLOR_TYPE_PALETTE )
        png_set_palette_to_rgb( p_png );

    if( i_color_type == PNG_COLOR_TYPE_GRAY ||
        i_color_type == PNG_COLOR_TYPE_GRAY_ALPHA )
          png_set_gray_to_rgb( p_png );

    /* Strip to 8 bits per channel */
    if( i_bit_depth == 16 ) png_set_strip_16( p_png );

    if( png_get_valid( p_png, p_info, PNG_INFO_tRNS ) )
    {
        png_set_tRNS_to_alpha( p_png );
    }
    else if( !(i_color_type & PNG_COLOR_MASK_ALPHA) )
    {
        p_dec->fmt_out.i_codec = VLC_CODEC_RGB24;
    }

    /* Get a new picture */
    p_pic = decoder_NewPicture( p_dec );
    if( !p_pic ) goto error;
//.........这里部分代码省略.........

/****************************************************************************
 * DecodeBlock: the whole thing
 ****************************************************************************
 * This function must be fed with a complete image.
 ****************************************************************************/
static int DecodeBlock( decoder_t *p_dec, block_t *p_block )
{
    decoder_sys_t *p_sys  = (decoder_sys_t *) p_dec->p_sys;
    picture_t *p_pic = NULL;
    int32_t i_width, i_height;

    RsvgHandle *rsvg = NULL;
    cairo_surface_t *surface = NULL;
    cairo_t *cr = NULL;

    if( p_block == NULL ) /* No Drain */
        return VLCDEC_SUCCESS;

    if( p_block->i_flags & BLOCK_FLAG_CORRUPTED)
    {
        block_Release( p_block );
        return VLCDEC_SUCCESS;
    }

    rsvg = rsvg_handle_new_from_data( p_block->p_buffer, p_block->i_buffer, NULL );
    if( !rsvg )
        goto done;

    RsvgDimensionData dim;
    rsvg_handle_get_dimensions( rsvg, &dim );

    if( p_sys->f_scale > 0.0 )
    {
        i_width  = (int32_t)(p_sys->f_scale * dim.width);
        i_height = (int32_t)(p_sys->f_scale * dim.height);
    }
    else
    {
        /* Keep aspect */
        if( p_sys->i_width < 0 && p_sys->i_height > 0 )
        {
            i_width  = dim.width * p_sys->i_height / dim.height;
            i_height = p_sys->i_height;
        }
        else if( p_sys->i_width > 0 && p_sys->i_height < 0 )
        {
            i_width  = p_sys->i_width;
            i_height = dim.height * p_sys->i_width / dim.height;
        }
        else if( p_sys->i_width > 0 && p_sys->i_height > 0 )
        {
            i_width  = dim.width * p_sys->i_height / dim.height;
            i_height = p_sys->i_height;
        }
        else
        {
            i_width  = dim.width;
            i_height = dim.height;
        }
    }

    p_dec->fmt_out.i_codec =
    p_dec->fmt_out.video.i_chroma = VLC_CODEC_BGRA;
    p_dec->fmt_out.video.i_width  = i_width;
    p_dec->fmt_out.video.i_height = i_height;
    p_dec->fmt_out.video.i_visible_width  = i_width;
    p_dec->fmt_out.video.i_visible_height = i_height;
    p_dec->fmt_out.video.i_sar_num = 1;
    p_dec->fmt_out.video.i_sar_den = 1;
    p_dec->fmt_out.video.i_rmask = 0x80800000; /* Since librsvg v1.0 */
    p_dec->fmt_out.video.i_gmask = 0x0000ff00;
    p_dec->fmt_out.video.i_bmask = 0x000000ff;
    video_format_FixRgb(&p_dec->fmt_out.video);

    /* Get a new picture */
    if( decoder_UpdateVideoFormat( p_dec ) )
        goto done;
    p_pic = decoder_NewPicture( p_dec );
    if( !p_pic )
        goto done;

    /* NOTE: Do not use the stride calculation from cairo, because it is wrong:
     * stride = cairo_format_stride_for_width(CAIRO_FORMAT_ARGB32, dim.width);
     * Use the stride from VLC its picture_t::p[0].i_pitch, which is correct.
     */
    memset(p_pic->p[0].p_pixels, 0, p_pic->p[0].i_pitch * p_pic->p[0].i_lines);
    surface = cairo_image_surface_create_for_data( p_pic->p->p_pixels,
                                                   CAIRO_FORMAT_ARGB32,
                                                   i_width, i_height,
                                                   p_pic->p[0].i_pitch );
    if( !surface )
    {
        picture_Release( p_pic );
        p_pic = NULL;
        goto done;
    }

    /* Decode picture */
    cr = cairo_create( surface );
    if( !cr )
//.........这里部分代码省略.........

/* Returns a new picture buffer */
static inline picture_t *ffmpeg_NewPictBuf( decoder_t *p_dec,
                                            AVCodecContext *p_context )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    int width = p_context->coded_width;
    int height = p_context->coded_height;

    if( p_sys->p_va == NULL )
    {
        int aligns[AV_NUM_DATA_POINTERS];

        avcodec_align_dimensions2(p_context, &width, &height, aligns);
    }


    if( width == 0 || height == 0 || width > 8192 || height > 8192 )
    {
        msg_Err( p_dec, "Invalid frame size %dx%d.", width, height );
        return NULL; /* invalid display size */
    }
    p_dec->fmt_out.video.i_width = width;
    p_dec->fmt_out.video.i_height = height;

    if( width != p_context->width || height != p_context->height )
    {
        p_dec->fmt_out.video.i_visible_width = p_context->width;
        p_dec->fmt_out.video.i_visible_height = p_context->height;
    }
    else
    {
        p_dec->fmt_out.video.i_visible_width = width;
        p_dec->fmt_out.video.i_visible_height = height;
    }

    if( !p_sys->p_va && GetVlcChroma( &p_dec->fmt_out.video, p_context->pix_fmt ) )
    {
        /* we are doomed, but not really, because most codecs set their pix_fmt
         * much later
         * FIXME does it make sense here ? */
        p_dec->fmt_out.video.i_chroma = VLC_CODEC_I420;
    }
    p_dec->fmt_out.i_codec = p_dec->fmt_out.video.i_chroma;

    /* If an aspect-ratio was specified in the input format then force it */
    if( p_dec->fmt_in.video.i_sar_num > 0 && p_dec->fmt_in.video.i_sar_den > 0 )
    {
        p_dec->fmt_out.video.i_sar_num = p_dec->fmt_in.video.i_sar_num;
        p_dec->fmt_out.video.i_sar_den = p_dec->fmt_in.video.i_sar_den;
    }
    else
    {
        p_dec->fmt_out.video.i_sar_num = p_context->sample_aspect_ratio.num;
        p_dec->fmt_out.video.i_sar_den = p_context->sample_aspect_ratio.den;

        if( !p_dec->fmt_out.video.i_sar_num || !p_dec->fmt_out.video.i_sar_den )
        {
            p_dec->fmt_out.video.i_sar_num = 1;
            p_dec->fmt_out.video.i_sar_den = 1;
        }
    }

    if( p_dec->fmt_in.video.i_frame_rate > 0 &&
        p_dec->fmt_in.video.i_frame_rate_base > 0 )
    {
        p_dec->fmt_out.video.i_frame_rate =
            p_dec->fmt_in.video.i_frame_rate;
        p_dec->fmt_out.video.i_frame_rate_base =
            p_dec->fmt_in.video.i_frame_rate_base;
    }
    else if( p_context->time_base.num > 0 && p_context->time_base.den > 0 )
    {
        p_dec->fmt_out.video.i_frame_rate = p_context->time_base.den;
        p_dec->fmt_out.video.i_frame_rate_base = p_context->time_base.num * __MAX( p_context->ticks_per_frame, 1 );
    }

    return decoder_NewPicture( p_dec );
}