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WebM VP8 Codec SDK
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This example adds postprocessing to the simple decoder loop.
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.
/* 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");
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 the frame with 15ms deadline */ if(vpx_codec_decode(&codec, frame, frame_sz, NULL, 15000)) die_codec(&codec, "Failed to decode frame");
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.
#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
/* Copyright (c) 2010 The WebM project authors. All Rights Reserved. Use of this source code is governed by a BSD-style license that can be found in the LICENSE file in the root of the source tree. An additional intellectual property rights grant can be found in the file PATENTS. All contributing project authors may be found in the AUTHORS file in the root of the source tree. */ /* This example adds postprocessing to the simple decoder loop. */ #include <stdarg.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #define VPX_CODEC_DISABLE_COMPAT 1 #include "./vpx_config.h" #include "vpx/vp8dx.h" #include "vpx/vpx_decoder.h" #define interface (vpx_codec_vp8_dx()) #define IVF_FILE_HDR_SZ (32) #define IVF_FRAME_HDR_SZ (12) static unsigned int mem_get_le32(const unsigned char *mem) { return (mem[3] << 24)|(mem[2] << 16)|(mem[1] << 8)|(mem[0]); } static void die(const char *fmt, ...) { va_list ap; va_start(ap, fmt); vprintf(fmt, ap); if(fmt[strlen(fmt)-1] != '\n') printf("\n"); exit(EXIT_FAILURE); } static void die_codec(vpx_codec_ctx_t *ctx, const char *s) { const char *detail = vpx_codec_error_detail(ctx); printf("%s: %s\n", s, vpx_codec_error(ctx)); if(detail) printf(" %s\n",detail); exit(EXIT_FAILURE); } int main(int argc, char **argv) { FILE *infile, *outfile; vpx_codec_ctx_t codec; int flags = 0, frame_cnt = 0; unsigned char file_hdr[IVF_FILE_HDR_SZ]; unsigned char frame_hdr[IVF_FRAME_HDR_SZ]; unsigned char frame[256*1024]; vpx_codec_err_t res; (void)res; /* Open files */ if(argc!=3) die("Usage: %s <infile> <outfile>\n", argv[0]); if(!(infile = fopen(argv[1], "rb"))) die("Failed to open %s for reading", argv[1]); if(!(outfile = fopen(argv[2], "wb"))) die("Failed to open %s for writing", argv[2]); /* Read file header */ if(!(fread(file_hdr, 1, IVF_FILE_HDR_SZ, infile) == IVF_FILE_HDR_SZ && file_hdr[0]=='D' && file_hdr[1]=='K' && file_hdr[2]=='I' && file_hdr[3]=='F')) die("%s is not an IVF file.", argv[1]); printf("Using %s\n",vpx_codec_iface_name(interface)); /* 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"); // /* Read each frame */ while(fread(frame_hdr, 1, IVF_FRAME_HDR_SZ, infile) == IVF_FRAME_HDR_SZ) { int frame_sz = mem_get_le32(frame_hdr); vpx_codec_iter_t iter = NULL; vpx_image_t *img; frame_cnt++; if(frame_sz > sizeof(frame)) die("Frame %d data too big for example code buffer", frame_sz); if(fread(frame, 1, frame_sz, infile) != frame_sz) die("Frame %d failed to read complete frame", frame_cnt); #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 // /* Decode the frame with 15ms deadline */ // if(vpx_codec_decode(&codec, frame, frame_sz, NULL, 15000)) // die_codec(&codec, "Failed to decode frame"); // /* Write decoded data to disk */ while((img = vpx_codec_get_frame(&codec, &iter))) { unsigned int plane, y; for(plane=0; plane < 3; plane++) { unsigned char *buf =img->planes[plane]; for(y=0; y < (plane ? (img->d_h + 1) >> 1 : img->d_h); y++) { (void) fwrite(buf, 1, (plane ? (img->d_w + 1) >> 1 : img->d_w), outfile); buf += img->stride[plane]; } } } } printf("Processed %d frames.\n",frame_cnt); if(vpx_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec"); fclose(outfile); fclose(infile); return EXIT_SUCCESS; }
1.8.8