+static int alloc_buffer(InputStream *ist, FrameBuffer **pbuf)
+{
+ AVCodecContext *s = ist->st->codec;
+ FrameBuffer *buf = av_mallocz(sizeof(*buf));
+ int ret;
+ const int pixel_size = av_pix_fmt_descriptors[s->pix_fmt].comp[0].step_minus1+1;
+ int h_chroma_shift, v_chroma_shift;
+ int edge = 32; // XXX should be avcodec_get_edge_width(), but that fails on svq1
+ int w = s->width, h = s->height;
+
+ if (!buf)
+ return AVERROR(ENOMEM);
+
+ if (!(s->flags & CODEC_FLAG_EMU_EDGE)) {
+ w += 2*edge;
+ h += 2*edge;
+ }
+
+ avcodec_align_dimensions(s, &w, &h);
+ if ((ret = av_image_alloc(buf->base, buf->linesize, w, h,
+ s->pix_fmt, 32)) < 0) {
+ av_freep(&buf);
+ return ret;
+ }
+ /* XXX this shouldn't be needed, but some tests break without this line
+ * those decoders are buggy and need to be fixed.
+ * the following tests fail:
+ * bethsoft-vid, cdgraphics, ansi, aasc, fraps-v1, qtrle-1bit
+ */
+ memset(buf->base[0], 128, ret);
+
+ avcodec_get_chroma_sub_sample(s->pix_fmt, &h_chroma_shift, &v_chroma_shift);
+ for (int i = 0; i < FF_ARRAY_ELEMS(buf->data); i++) {
+ const int h_shift = i==0 ? 0 : h_chroma_shift;
+ const int v_shift = i==0 ? 0 : v_chroma_shift;
+ if (s->flags & CODEC_FLAG_EMU_EDGE)
+ buf->data[i] = buf->base[i];
+ else
+ buf->data[i] = buf->base[i] +
+ FFALIGN((buf->linesize[i]*edge >> v_shift) +
+ (pixel_size*edge >> h_shift), 32);
+ }
+ buf->w = s->width;
+ buf->h = s->height;
+ buf->pix_fmt = s->pix_fmt;
+ buf->ist = ist;
+
+ *pbuf = buf;
+ return 0;
+}
+
+static void free_buffer_pool(InputStream *ist)
+{
+ FrameBuffer *buf = ist->buffer_pool;
+ while (buf) {
+ ist->buffer_pool = buf->next;
+ av_freep(&buf->base[0]);
+ av_free(buf);
+ buf = ist->buffer_pool;
+ }
+}
+
+static void unref_buffer(InputStream *ist, FrameBuffer *buf)
+{
+ av_assert0(buf->refcount);
+ buf->refcount--;
+ if (!buf->refcount) {
+ buf->next = ist->buffer_pool;
+ ist->buffer_pool = buf;
+ }
+}
+
+static int codec_get_buffer(AVCodecContext *s, AVFrame *frame)
+{
+ InputStream *ist = s->opaque;
+ FrameBuffer *buf;
+ int ret, i;
+
+ if (!ist->buffer_pool && (ret = alloc_buffer(ist, &ist->buffer_pool)) < 0)
+ return ret;
+
+ buf = ist->buffer_pool;
+ ist->buffer_pool = buf->next;
+ buf->next = NULL;
+ if (buf->w != s->width || buf->h != s->height || buf->pix_fmt != s->pix_fmt) {
+ av_freep(&buf->base[0]);
+ av_free(buf);
+ if ((ret = alloc_buffer(ist, &buf)) < 0)
+ return ret;
+ }
+ buf->refcount++;
+
+ frame->opaque = buf;
+ frame->type = FF_BUFFER_TYPE_USER;
+ frame->extended_data = frame->data;
+ frame->pkt_pts = s->pkt ? s->pkt->pts : AV_NOPTS_VALUE;
+
+ for (i = 0; i < FF_ARRAY_ELEMS(buf->data); i++) {
+ frame->base[i] = buf->base[i]; // XXX h264.c uses base though it shouldn't
+ frame->data[i] = buf->data[i];
+ frame->linesize[i] = buf->linesize[i];
+ }
+
+ return 0;
+}
+
+static void codec_release_buffer(AVCodecContext *s, AVFrame *frame)
+{
+ InputStream *ist = s->opaque;
+ FrameBuffer *buf = frame->opaque;
+ int i;
+
+ for (i = 0; i < FF_ARRAY_ELEMS(frame->data); i++)
+ frame->data[i] = NULL;
+
+ unref_buffer(ist, buf);
+}
+
+static void filter_release_buffer(AVFilterBuffer *fb)
+{
+ FrameBuffer *buf = fb->priv;
+ av_free(fb);
+ unref_buffer(buf->ist, buf);
+}
+