1 /*
2 * Copyright (c) 2013 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 #include <stdio.h>
12 #include <stdlib.h>
13 #include <string.h>
14
15 #include "vpx_ports/mem_ops.h"
16
17 #include "./ivfdec.h"
18
19 static const char *IVF_SIGNATURE = "DKIF";
20
fix_framerate(int * num,int * den)21 static void fix_framerate(int *num, int *den) {
22 // Some versions of vpxenc used 1/(2*fps) for the timebase, so
23 // we can guess the framerate using only the timebase in this
24 // case. Other files would require reading ahead to guess the
25 // timebase, like we do for webm.
26 if (*num < 1000) {
27 // Correct for the factor of 2 applied to the timebase in the encoder.
28 if (*num & 1)
29 *den *= 2;
30 else
31 *num /= 2;
32 } else {
33 // Don't know FPS for sure, and don't have readahead code
34 // (yet?), so just default to 30fps.
35 *num = 30;
36 *den = 1;
37 }
38 }
39
file_is_ivf(struct VpxInputContext * input_ctx)40 int file_is_ivf(struct VpxInputContext *input_ctx) {
41 char raw_hdr[32];
42 int is_ivf = 0;
43
44 if (fread(raw_hdr, 1, 32, input_ctx->file) == 32) {
45 if (memcmp(IVF_SIGNATURE, raw_hdr, 4) == 0) {
46 is_ivf = 1;
47
48 if (mem_get_le16(raw_hdr + 4) != 0) {
49 fprintf(stderr, "Error: Unrecognized IVF version! This file may not"
50 " decode properly.");
51 }
52
53 input_ctx->fourcc = mem_get_le32(raw_hdr + 8);
54 input_ctx->width = mem_get_le16(raw_hdr + 12);
55 input_ctx->height = mem_get_le16(raw_hdr + 14);
56 input_ctx->framerate.numerator = mem_get_le32(raw_hdr + 16);
57 input_ctx->framerate.denominator = mem_get_le32(raw_hdr + 20);
58 fix_framerate(&input_ctx->framerate.numerator,
59 &input_ctx->framerate.denominator);
60 }
61 }
62
63 if (!is_ivf) {
64 rewind(input_ctx->file);
65 input_ctx->detect.buf_read = 0;
66 } else {
67 input_ctx->detect.position = 4;
68 }
69 return is_ivf;
70 }
71
ivf_read_frame(FILE * infile,uint8_t ** buffer,size_t * bytes_read,size_t * buffer_size)72 int ivf_read_frame(FILE *infile, uint8_t **buffer,
73 size_t *bytes_read, size_t *buffer_size) {
74 char raw_header[IVF_FRAME_HDR_SZ] = {0};
75 size_t frame_size = 0;
76
77 if (fread(raw_header, IVF_FRAME_HDR_SZ, 1, infile) != 1) {
78 if (!feof(infile))
79 warn("Failed to read frame size\n");
80 } else {
81 frame_size = mem_get_le32(raw_header);
82
83 if (frame_size > 256 * 1024 * 1024) {
84 warn("Read invalid frame size (%u)\n", (unsigned int)frame_size);
85 frame_size = 0;
86 }
87
88 if (frame_size > *buffer_size) {
89 uint8_t *new_buffer = realloc(*buffer, 2 * frame_size);
90
91 if (new_buffer) {
92 *buffer = new_buffer;
93 *buffer_size = 2 * frame_size;
94 } else {
95 warn("Failed to allocate compressed data buffer\n");
96 frame_size = 0;
97 }
98 }
99 }
100
101 if (!feof(infile)) {
102 if (fread(*buffer, 1, frame_size, infile) != frame_size) {
103 warn("Failed to read full frame\n");
104 return 1;
105 }
106
107 *bytes_read = frame_size;
108 return 0;
109 }
110
111 return 1;
112 }
113