aom/video_reader.c

84 строки
2.2 KiB
C

/*
* Copyright (c) 2014 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.
*/
#include <stdlib.h>
#include <string.h>
#include "./ivfdec.h"
#include "./video_reader.h"
#include "vpx_ports/mem_ops.h"
static const char *const kIVFSignature = "DKIF";
struct VpxVideoReaderStruct {
VpxVideoInfo info;
FILE *file;
uint8_t *buffer;
size_t buffer_size;
size_t frame_size;
};
VpxVideoReader *vpx_video_reader_open(const char *filename) {
char header[32];
VpxVideoReader *reader = NULL;
FILE *const file = fopen(filename, "rb");
if (!file)
return NULL; // Can't open file
if (fread(header, 1, 32, file) != 32)
return NULL; // Can't read file header
if (memcmp(kIVFSignature, header, 4) != 0)
return NULL; // Wrong IVF signature
if (mem_get_le16(header + 4) != 0)
return NULL; // Wrong IVF version
reader = calloc(1, sizeof(*reader));
if (!reader)
return NULL; // Can't allocate VpxVideoReader
reader->file = file;
reader->info.codec_fourcc = mem_get_le32(header + 8);
reader->info.frame_width = mem_get_le16(header + 12);
reader->info.frame_height = mem_get_le16(header + 14);
reader->info.time_base.numerator = mem_get_le32(header + 16);
reader->info.time_base.denominator = mem_get_le32(header + 20);
return reader;
}
void vpx_video_reader_close(VpxVideoReader *reader) {
if (reader) {
fclose(reader->file);
free(reader->buffer);
free(reader);
}
}
int vpx_video_reader_read_frame(VpxVideoReader *reader) {
return !ivf_read_frame(reader->file, &reader->buffer, &reader->frame_size,
&reader->buffer_size);
}
const uint8_t *vpx_video_reader_get_frame(VpxVideoReader *reader,
size_t *size) {
if (size)
*size = reader->frame_size;
return reader->buffer;
}
const VpxVideoInfo *vpx_video_reader_get_info(VpxVideoReader *reader) {
return &reader->info;
}