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 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 (*den > 0 && *den < 1000000000 && *num > 0 && *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 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, 50 "Error: Unrecognized IVF version! This file may not" 51 " decode properly."); 52 } 53 54 input_ctx->fourcc = mem_get_le32(raw_hdr + 8); 55 input_ctx->width = mem_get_le16(raw_hdr + 12); 56 input_ctx->height = mem_get_le16(raw_hdr + 14); 57 input_ctx->framerate.numerator = mem_get_le32(raw_hdr + 16); 58 input_ctx->framerate.denominator = mem_get_le32(raw_hdr + 20); 59 fix_framerate(&input_ctx->framerate.numerator, 60 &input_ctx->framerate.denominator); 61 } 62 } 63 64 if (!is_ivf) { 65 rewind(input_ctx->file); 66 input_ctx->detect.buf_read = 0; 67 } else { 68 input_ctx->detect.position = 4; 69 } 70 return is_ivf; 71 } 72 73 int ivf_read_frame(FILE *infile, uint8_t **buffer, size_t *bytes_read, 74 size_t *buffer_size) { 75 char raw_header[IVF_FRAME_HDR_SZ] = { 0 }; 76 size_t frame_size = 0; 77 78 if (fread(raw_header, IVF_FRAME_HDR_SZ, 1, infile) != 1) { 79 if (!feof(infile)) 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
