+int codec_get_buffer(AVCodecContext *s, AVFrame *frame);
+
+/**
+ * A callback to be used for AVCodecContext.release_buffer along with
+ * codec_get_buffer().
+ */
+void codec_release_buffer(AVCodecContext *s, AVFrame *frame);
+
+/**
+ * A callback to be used for AVFilterBuffer.free.
+ * @param fb buffer to free. fb->priv must be a pointer to the FrameBuffer
+ * containing the buffer data.
+ */
+void filter_release_buffer(AVFilterBuffer *fb);
+
+/**
+ * Free all the buffers in the pool. This must be called after all the
+ * buffers have been released.
+ */
+void free_buffer_pool(FrameBuffer **pool);
+
+#define GET_PIX_FMT_NAME(pix_fmt)\
+ const char *name = av_get_pix_fmt_name(pix_fmt);
+
+#define GET_SAMPLE_FMT_NAME(sample_fmt)\
+ const char *name = av_get_sample_fmt_name(sample_fmt)
+
+#define GET_SAMPLE_RATE_NAME(rate)\
+ char name[16];\
+ snprintf(name, sizeof(name), "%d", rate);
+
+#define GET_CH_LAYOUT_NAME(ch_layout)\
+ char name[16];\
+ snprintf(name, sizeof(name), "0x%"PRIx64, ch_layout);
+
+#define GET_CH_LAYOUT_DESC(ch_layout)\
+ char name[128];\
+ av_get_channel_layout_string(name, sizeof(name), 0, ch_layout);