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. 33// 34// Initializing The Codec 35// ---------------------- 36// The decoder is initialized by the following code. This is an example for 37// the VP8 decoder, but the code is analogous for all algorithms. Replace 38// `vpx_codec_vp8_dx()` with a pointer to the interface exposed by the 39// algorithm you want to use. The `cfg` argument is left as NULL in this 40// example, because we want the algorithm to determine the stream 41// configuration (width/height) and allocate memory automatically. This 42// parameter is generally only used if you need to preallocate memory, 43// particularly in External Memory Allocation mode. 44// 45// Decoding A Frame 46// ---------------- 47// Once the frame has been read into memory, it is decoded using the 48// `vpx_codec_decode` function. The call takes a pointer to the data 49// (`frame`) and the length of the data (`frame_sz`). No application data 50// is associated with the frame in this example, so the `user_priv` 51// parameter is NULL. The `deadline` parameter is left at zero for this 52// example. This parameter is generally only used when doing adaptive 53// postprocessing. 54// 55// Codecs may produce a variable number of output frames for every call to 56// `vpx_codec_decode`. These frames are retrieved by the 57// `vpx_codec_get_frame` iterator function. The iterator variable `iter` is 58// initialized to NULL each time `vpx_codec_decode` is called. 59// `vpx_codec_get_frame` is called in a loop, returning a pointer to a 60// decoded image or NULL to indicate the end of list. 61// 62// Processing The Decoded Data 63// --------------------------- 64// In this example, we simply write the encoded data to disk. It is 65// important to honor the image's `stride` values. 66// 67// Cleanup 68// ------- 69// The `vpx_codec_destroy` call frees any memory allocated by the codec. 70// 71// Error Handling 72// -------------- 73// This example does not special case any error return codes. If there was 74// an error, a descriptive message is printed and the program exits. With 75// few exeptions, vpx_codec functions return an enumerated error status, 76// with the value `0` indicating success. 77 78#include <stdio.h> 79#include <stdlib.h> 80#include <string.h> 81 82#include "vpx/vp8dx.h" 83#include "vpx/vpx_decoder.h" 84 85#include "./tools_common.h" 86#include "./video_reader.h" 87#include "./vpx_config.h" 88 89static const char *exec_name; 90 91void usage_exit() { 92 fprintf(stderr, "Usage: %s <infile> <outfile>\n", exec_name); 93 exit(EXIT_FAILURE); 94} 95 96int main(int argc, char **argv) { 97 int frame_cnt = 0; 98 FILE *outfile = NULL; 99 vpx_codec_ctx_t codec; 100 VpxVideoReader *reader = NULL; 101 const VpxInterface *decoder = NULL; 102 const VpxVideoInfo *info = NULL; 103 104 exec_name = argv[0]; 105 106 if (argc != 3) 107 die("Invalid number of arguments."); 108 109 reader = vpx_video_reader_open(argv[1]); 110 if (!reader) 111 die("Failed to open %s for reading.", argv[1]); 112 113 if (!(outfile = fopen(argv[2], "wb"))) 114 die("Failed to open %s for writing.", argv[2]); 115 116 info = vpx_video_reader_get_info(reader); 117 118 decoder = get_vpx_decoder_by_fourcc(info->codec_fourcc); 119 if (!decoder) 120 die("Unknown input codec."); 121 122 printf("Using %s\n", vpx_codec_iface_name(decoder->codec_interface())); 123 124 if (vpx_codec_dec_init(&codec, decoder->codec_interface(), NULL, 0)) 125 die_codec(&codec, "Failed to initialize decoder."); 126 127 while (vpx_video_reader_read_frame(reader)) { 128 vpx_codec_iter_t iter = NULL; 129 vpx_image_t *img = NULL; 130 size_t frame_size = 0; 131 const unsigned char *frame = vpx_video_reader_get_frame(reader, 132 &frame_size); 133 if (vpx_codec_decode(&codec, frame, (unsigned int)frame_size, NULL, 0)) 134 die_codec(&codec, "Failed to decode frame."); 135 136 while ((img = vpx_codec_get_frame(&codec, &iter)) != NULL) { 137 vpx_img_write(img, outfile); 138 ++frame_cnt; 139 } 140 } 141 142 printf("Processed %d frames.\n", frame_cnt); 143 if (vpx_codec_destroy(&codec)) 144 die_codec(&codec, "Failed to destroy codec"); 145 146 printf("Play: ffplay -f rawvideo -pix_fmt yuv420p -s %dx%d %s\n", 147 info->frame_width, info->frame_height, argv[2]); 148 149 vpx_video_reader_close(reader); 150 151 fclose(outfile); 152 153 return EXIT_SUCCESS; 154} 155