Function input_get_buffer

ffplay.c:1565–1606

} FilterPriv;

static int input_get_buffer(AVCodecContext *codec, AVFrame *pic)
{
    AVFilterContext *ctx = codec->opaque;
    AVFilterPicRef  *ref;
    int perms = AV_PERM_WRITE;
    int w, h, stride[4];
    unsigned edge;

    if(pic->buffer_hints & FF_BUFFER_HINTS_VALID) {
        if(pic->buffer_hints & FF_BUFFER_HINTS_READABLE) perms |= AV_PERM_READ;
        if(pic->buffer_hints & FF_BUFFER_HINTS_PRESERVE) perms |= AV_PERM_PRESERVE;
        if(pic->buffer_hints & FF_BUFFER_HINTS_REUSABLE) perms |= AV_PERM_REUSE2;
    }
    if(pic->reference) perms |= AV_PERM_READ | AV_PERM_PRESERVE;

    w = codec->width;
    h = codec->height;
    avcodec_align_dimensions2(codec, &w, &h, stride);
    edge = codec->flags & CODEC_FLAG_EMU_EDGE ? 0 : avcodec_get_edge_width();
    w += edge << 1;
    h += edge << 1;

    if(!(ref = avfilter_get_video_buffer(ctx->outputs[0], perms, w, h)))
        return -1;

    ref->w = codec->width;
    ref->h = codec->height;
    for(int i = 0; i < 3; i ++) {
        unsigned hshift = i == 0 ? 0 : av_pix_fmt_descriptors[ref->pic->format].log2_chroma_w;
        unsigned vshift = i == 0 ? 0 : av_pix_fmt_descriptors[ref->pic->format].log2_chroma_h;

        if (ref->data[i]) {
            ref->data[i]    += (edge >> hshift) + ((edge * ref->linesize[i]) >> vshift);
        }
        pic->data[i]     = ref->data[i];
        pic->linesize[i] = ref->linesize[i];
    }
    pic->opaque = ref;
    pic->age    = INT_MAX;
    pic->type   = FF_BUFFER_TYPE_USER;
    return 0;
}

static void input_release_buffer(AVCodecContext *codec, AVFrame *pic)
{