1/* 2 * Copyright (c) 2010 The WebM project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 12// Simple Decoder 13// ============== 14// 15// This is an example of a simple decoder loop. It takes an input file 16// containing the compressed data (in IVF format), passes it through the 17// decoder, and writes the decompressed frames to disk. Other decoder 18// examples build upon this one. 19// 20// The details of the IVF format have been elided from this example for 21// simplicity of presentation, as IVF files will not generally be used by 22// your application. In general, an IVF file consists of a file header, 23// followed by a variable number of frames. Each frame consists of a frame 24// header followed by a variable length payload. The length of the payload 25// is specified in the first four bytes of the frame header. The payload is 26// the raw compressed data. 27// 28// Standard Includes 29// ----------------- 30// For decoders, you only have to include `vpx_decoder.h` and then any 31// header files for the specific codecs you use. In this case, we're using 32// vp8. The `VPX_CODEC_DISABLE_COMPAT` macro can be defined to ensure 33// strict compliance with the latest SDK by disabling some backwards 34// compatibility features. Defining this macro is encouraged. 35// 36// Initializing The Codec 37// ---------------------- 38// The decoder is initialized by the following code. This is an example for 39// the VP8 decoder, but the code is analogous for all algorithms. Replace 40// `vpx_codec_vp8_dx()` with a pointer to the interface exposed by the 41// algorithm you want to use. The `cfg` argument is left as NULL in this 42// example, because we want the algorithm to determine the stream 43// configuration (width/height) and allocate memory automatically. This 44// parameter is generally only used if you need to preallocate memory, 45// particularly in External Memory Allocation mode. 46// 47// Decoding A Frame 48// ---------------- 49// Once the frame has been read into memory, it is decoded using the 50// `vpx_codec_decode` function. The call takes a pointer to the data 51// (`frame`) and the length of the data (`frame_sz`). No application data 52// is associated with the frame in this example, so the `user_priv` 53// parameter is NULL. The `deadline` parameter is left at zero for this 54// example. This parameter is generally only used when doing adaptive 55// postprocessing. 56// 57// Codecs may produce a variable number of output frames for every call to 58// `vpx_codec_decode`. These frames are retrieved by the 59// `vpx_codec_get_frame` iterator function. The iterator variable `iter` is 60// initialized to NULL each time `vpx_codec_decode` is called. 61// `vpx_codec_get_frame` is called in a loop, returning a pointer to a 62// decoded image or NULL to indicate the end of list. 63// 64// Processing The Decoded Data 65// --------------------------- 66// In this example, we simply write the encoded data to disk. It is 67// important to honor the image's `stride` values. 68// 69// Cleanup 70// ------- 71// The `vpx_codec_destroy` call frees any memory allocated by the codec. 72// 73// Error Handling 74// -------------- 75// This example does not special case any error return codes. If there was 76// an error, a descriptive message is printed and the program exits. With 77// few exeptions, vpx_codec functions return an enumerated error status, 78// with the value `0` indicating success. 79 80#include <stdio.h> 81#include <stdlib.h> 82#include <string.h> 83 84#define VPX_CODEC_DISABLE_COMPAT 1 85 86#include "vpx/vp8dx.h" 87#include "vpx/vpx_decoder.h" 88 89#include "./tools_common.h" 90#include "./video_reader.h" 91#include "./vpx_config.h" 92 93static const char *exec_name; 94 95void usage_exit() { 96 fprintf(stderr, "Usage: %s <infile> <outfile>\n", exec_name); 97 exit(EXIT_FAILURE); 98} 99 100int main(int argc, char **argv) { 101 int frame_cnt = 0; 102 FILE *outfile = NULL; 103 vpx_codec_ctx_t codec; 104 VpxVideoReader *reader = NULL; 105 const VpxInterface *decoder = NULL; 106 const VpxVideoInfo *info = NULL; 107 108 exec_name = argv[0]; 109 110 if (argc != 3) 111 die("Invalid number of arguments."); 112 113 reader = vpx_video_reader_open(argv[1]); 114 if (!reader) 115 die("Failed to open %s for reading.", argv[1]); 116 117 if (!(outfile = fopen(argv[2], "wb"))) 118 die("Failed to open %s for writing.", argv[2]); 119 120 info = vpx_video_reader_get_info(reader); 121 122 decoder = get_vpx_decoder_by_fourcc(info->codec_fourcc); 123 if (!decoder) 124 die("Unknown input codec."); 125 126 printf("Using %s\n", vpx_codec_iface_name(decoder->interface())); 127 128 if (vpx_codec_dec_init(&codec, decoder->interface(), NULL, 0)) 129 die_codec(&codec, "Failed to initialize decoder."); 130 131 while (vpx_video_reader_read_frame(reader)) { 132 vpx_codec_iter_t iter = NULL; 133 vpx_image_t *img = NULL; 134 size_t frame_size = 0; 135 const unsigned char *frame = vpx_video_reader_get_frame(reader, 136 &frame_size); 137 if (vpx_codec_decode(&codec, frame, (unsigned int)frame_size, NULL, 0)) 138 die_codec(&codec, "Failed to decode frame."); 139 140 while ((img = vpx_codec_get_frame(&codec, &iter)) != NULL) { 141 vpx_img_write(img, outfile); 142 ++frame_cnt; 143 } 144 } 145 146 printf("Processed %d frames.\n", frame_cnt); 147 if (vpx_codec_destroy(&codec)) 148 die_codec(&codec, "Failed to destroy codec"); 149 150 printf("Play: ffplay -f rawvideo -pix_fmt yuv420p -s %dx%d %s\n", 151 info->frame_width, info->frame_height, argv[2]); 152 153 vpx_video_reader_close(reader); 154 155 fclose(outfile); 156 157 return EXIT_SUCCESS; 158} 159