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/*
* Copyright (c) 2013 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "./ivfdec.h"
static const char *IVF_SIGNATURE = "DKIF";
static void fix_framerate(int *num, int *den) {
// Some versions of vpxenc used 1/(2*fps) for the timebase, so
// we can guess the framerate using only the timebase in this
// case. Other files would require reading ahead to guess the
// timebase, like we do for webm.
if (*num < 1000) {
// Correct for the factor of 2 applied to the timebase in the encoder.
if (*num & 1)
*den *= 2;
else
*num /= 2;
} else {
// Don't know FPS for sure, and don't have readahead code
// (yet?), so just default to 30fps.
*num = 30;
*den = 1;
}
}
int file_is_ivf(struct VpxInputContext *input_ctx) {
char raw_hdr[32];
int is_ivf = 0;
if (fread(raw_hdr, 1, 32, input_ctx->file) == 32) {
if (memcmp(IVF_SIGNATURE, raw_hdr, 4) == 0) {
is_ivf = 1;
if (mem_get_le16(raw_hdr + 4) != 0) {
fprintf(stderr, "Error: Unrecognized IVF version! This file may not"
" decode properly.");
}
input_ctx->fourcc = mem_get_le32(raw_hdr + 8);
input_ctx->width = mem_get_le16(raw_hdr + 12);
input_ctx->height = mem_get_le16(raw_hdr + 14);
input_ctx->framerate.numerator = mem_get_le32(raw_hdr + 16);
input_ctx->framerate.denominator = mem_get_le32(raw_hdr + 20);
fix_framerate(&input_ctx->framerate.numerator,
&input_ctx->framerate.denominator);
}
}
if (!is_ivf) {
rewind(input_ctx->file);
input_ctx->detect.buf_read = 0;
} else {
input_ctx->detect.position = 4;
}
return is_ivf;
}
int ivf_read_frame(FILE *infile, uint8_t **buffer,
size_t *bytes_read, size_t *buffer_size) {
char raw_header[IVF_FRAME_HDR_SZ] = {0};
size_t frame_size = 0;
if (fread(raw_header, IVF_FRAME_HDR_SZ, 1, infile) != 1) {
if (!feof(infile))
warn("Failed to read frame size\n");
} else {
frame_size = mem_get_le32(raw_header);
if (frame_size > 256 * 1024 * 1024) {
warn("Read invalid frame size (%u)\n", (unsigned int)frame_size);
frame_size = 0;
}
if (frame_size > *buffer_size) {
uint8_t *new_buffer = realloc(*buffer, 2 * frame_size);
if (new_buffer) {
*buffer = new_buffer;
*buffer_size = 2 * frame_size;
} else {
warn("Failed to allocate compressed data buffer\n");
frame_size = 0;
}
}
}
if (!feof(infile)) {
if (fread(*buffer, 1, frame_size, infile) != frame_size) {
warn("Failed to read full frame\n");
return 1;
}
*bytes_read = frame_size;
return 0;
}
return 1;
}
struct vpx_video {
FILE *file;
unsigned char *buffer;
size_t buffer_size;
size_t frame_size;
unsigned int fourcc;
int width;
int height;
};
vpx_video_t *vpx_video_open_file(FILE *file) {
char raw_hdr[32];
vpx_video_t *video;
if (fread(raw_hdr, 1, 32, file) != 32)
return NULL; // Can't read file header;
if (memcmp(IVF_SIGNATURE, raw_hdr, 4) != 0)
return NULL; // Wrong IVF signature
if (mem_get_le16(raw_hdr + 4) != 0)
return NULL; // Wrong IVF version
video = (vpx_video_t *)malloc(sizeof(*video));
video->file = file;
video->buffer = NULL;
video->buffer_size = 0;
video->frame_size = 0;
video->fourcc = mem_get_le32(raw_hdr + 8);
video->width = mem_get_le16(raw_hdr + 12);
video->height = mem_get_le16(raw_hdr + 14);
return video;
}
void vpx_video_close(vpx_video_t *video) {
if (video) {
free(video->buffer);
free(video);
}
}
int vpx_video_get_width(vpx_video_t *video) {
return video->width;
}
int vpx_video_get_height(vpx_video_t *video) {
return video->height;
}
unsigned int vpx_video_get_fourcc(vpx_video_t *video) {
return video->fourcc;
}
int vpx_video_read_frame(vpx_video_t *video) {
return !ivf_read_frame(video->file, &video->buffer, &video->frame_size,
&video->buffer_size);
}
const unsigned char *vpx_video_get_frame(vpx_video_t *video, size_t *size) {
if (size)
*size = video->frame_size;
return video->buffer;
}
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