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Dmitry Kovalev authored
Right now only IVF format is supported which is enough for example code. Other formats like y4m, webm, raw yuv will be supported later. Change-Id: I34c6f20731c1851947587ca5c589d7856b675164
37e6fd3d
simple_decoder.c 5.55 KiB
/* * 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. */// Simple Decoder// ==============//// This is an example of a simple decoder loop. It takes an input file// containing the compressed data (in IVF format), passes it through the// decoder, and writes the decompressed frames to disk. Other decoder// examples build upon this one.//// The details of the IVF format have been elided from this example for// simplicity of presentation, as IVF files will not generally be used by// your application. In general, an IVF file consists of a file header,// followed by a variable number of frames. Each frame consists of a frame// header followed by a variable length payload. The length of the payload// is specified in the first four bytes of the frame header. The payload is// the raw compressed data.//// Standard Includes// -----------------// For decoders, you only have to include `vpx_decoder.h` and then any// header files for the specific codecs you use. In this case, we're using// vp8. The `VPX_CODEC_DISABLE_COMPAT` macro can be defined to ensure// strict compliance with the latest SDK by disabling some backwards// compatibility features. Defining this macro is encouraged.//// Initializing The Codec// ----------------------// The decoder is initialized by the following code. This is an example for// the VP8 decoder, but the code is analogous for all algorithms. Replace// `vpx_codec_vp8_dx()` with a pointer to the interface exposed by the// algorithm you want to use. The `cfg` argument is left as NULL in this// example, because we want the algorithm to determine the stream// configuration (width/height) and allocate memory automatically. This// parameter is generally only used if you need to preallocate memory,// particularly in External Memory Allocation mode.//// Decoding A Frame// ----------------// Once the frame has been read into memory, it is decoded using the// `vpx_codec_decode` function. The call takes a pointer to the data// (`frame`) and the length of the data (`frame_sz`). No application data// is associated with the frame in this example, so the `user_priv`// parameter is NULL. The `deadline` parameter is left at zero for this// example. This parameter is generally only used when doing adaptive// postprocessing.//// Codecs may produce a variable number of output frames for every call to// `vpx_codec_decode`. These frames are retrieved by the// `vpx_codec_get_frame` iterator function. The iterator variable `iter` is// initialized to NULL each time `vpx_codec_decode` is called.// `vpx_codec_get_frame` is called in a loop, returning a pointer to a// decoded image or NULL to indicate the end of list.//// Processing The Decoded Data// ---------------------------// In this example, we simply write the encoded data to disk. It is// important to honor the image's `stride` values.//// Cleanup// -------7172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140
// The `vpx_codec_destroy` call frees any memory allocated by the codec.
//
// Error Handling
// --------------
// This example does not special case any error return codes. If there was
// an error, a descriptive message is printed and the program exits. With
// few exeptions, vpx_codec functions return an enumerated error status,
// with the value `0` indicating success.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define VPX_CODEC_DISABLE_COMPAT 1
#include "vpx/vp8dx.h"
#include "vpx/vpx_decoder.h"
#include "./tools_common.h"
#include "./video_reader.h"
#include "./vpx_config.h"
static const char *exec_name;
void usage_exit() {
fprintf(stderr, "Usage: %s <infile> <outfile>\n", exec_name);
exit(EXIT_FAILURE);
}
int main(int argc, char **argv) {
int frame_cnt = 0;
FILE *outfile = NULL;
vpx_codec_ctx_t codec;
vpx_codec_iface_t *iface = NULL;
VpxVideoReader *reader = NULL;
const VpxVideoInfo *info = NULL;
exec_name = argv[0];
if (argc != 3)
die("Invalid number of arguments.");
reader = vpx_video_reader_open(argv[1]);
if (!reader)
die("Failed to open %s for reading.", argv[1]);
if (!(outfile = fopen(argv[2], "wb")))
die("Failed to open %s for writing.", argv[2]);
info = vpx_video_reader_get_info(reader);
iface = get_codec_interface(info->codec_fourcc);
if (!iface)
die("Unknown input codec.");
printf("Using %s\n", vpx_codec_iface_name(iface));
if (vpx_codec_dec_init(&codec, iface, NULL, 0))
die_codec(&codec, "Failed to initialize decoder.");
while (vpx_video_reader_read_frame(reader)) {
vpx_codec_iter_t iter = NULL;
vpx_image_t *img = NULL;
size_t frame_size = 0;
const unsigned char *frame = vpx_video_reader_get_frame(reader,
&frame_size);
if (vpx_codec_decode(&codec, frame, frame_size, NULL, 0))
die_codec(&codec, "Failed to decode frame.");
while ((img = vpx_codec_get_frame(&codec, &iter)) != NULL) {
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vpx_img_write(img, outfile);
++frame_cnt;
}
}
printf("Processed %d frames.\n", frame_cnt);
if (vpx_codec_destroy(&codec))
die_codec(&codec, "Failed to destroy codec");
printf("Play: ffplay -f rawvideo -pix_fmt yuv420p -s %dx%d %s\n",
info->frame_width, info->frame_height, argv[2]);
vpx_video_reader_close(reader);
fclose(outfile);
return EXIT_SUCCESS;
}