libvpx: Pull from upstream

source/libvpx/examples/postproc.txt

-@TEMPLATE decoder_tmpl.c
-Postprocessing Decoder
-======================
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ INTRODUCTION
-This example adds postprocessing to the simple decoder loop.
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ INTRODUCTION
-
-
-Initializing Postprocessing
----------------------------
-You must inform the codec that you might request postprocessing at
-initialization time. This is done by passing the VPX_CODEC_USE_POSTPROC
-flag to `vpx_codec_dec_init`. If the codec does not support
-postprocessing, this call will return VPX_CODEC_INCAPABLE. For
-demonstration purposes, we also fall back to default initialization if
-the codec does not provide support.
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ DEC_INIT
-/* Initialize codec */
-res = vpx_codec_dec_init(&codec, interface, NULL,
-                         VPX_CODEC_USE_POSTPROC);
-if(res == VPX_CODEC_INCAPABLE) {
-    printf("NOTICE: Postproc not supported by %s\n",
-           vpx_codec_iface_name(interface));
-    res = vpx_codec_dec_init(&codec, interface, NULL, flags);
-}
-if(res)
-    die_codec(&codec, "Failed to initialize decoder");
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ DEC_INIT
-
-
-Using Adaptive Postprocessing
------------------------------
-VP6 provides "adaptive postprocessing." It will automatically select the
-best postprocessing filter on a frame by frame basis based on the amount
-of time remaining before the user's specified deadline expires. The
-special value 0 indicates that the codec should take as long as
-necessary to provide the best quality frame. This example gives the
-codec 15ms (15000us) to return a frame. Remember that this is a soft
-deadline, and the codec may exceed it doing its regular processing. In
-these cases, no additional postprocessing will be done.
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ DECODE
-/* Decode the frame with 15ms deadline */
-if(vpx_codec_decode(&codec, frame, frame_sz, NULL, 15000))
-    die_codec(&codec, "Failed to decode frame");
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ DECODE
-
-
-Codec Specific Postprocessing Controls
---------------------------------------
-Some codecs provide fine grained controls over their built-in
-postprocessors. VP8 is one example. The following sample code toggles
-postprocessing on and off every 15 frames.
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PRE_DECODE
-#if CONFIG_VP9_DECODER
-if(frame_cnt%30 == 1) {
-    vp8_postproc_cfg_t  pp = {0, 0, 0};
-
-    if(vpx_codec_control(&codec, VP8_SET_POSTPROC, &pp))
-        die_codec(&codec, "Failed to turn off postproc");
-} else if(frame_cnt%30 == 16) {
-    vp8_postproc_cfg_t  pp = {VP8_DEBLOCK | VP8_DEMACROBLOCK | VP8_MFQE, 4, 0};
-
-    if(vpx_codec_control(&codec, VP8_SET_POSTPROC, &pp))
-        die_codec(&codec, "Failed to turn on postproc");
-};
-#endif
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PRE_DECODE