ivfdec.c

   1 /*
   2  * Copyright (c) 2016, Alliance for Open Media. All rights reserved
   3  *
   4  * This source code is subject to the terms of the BSD 2 Clause License and
   5  * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
   6  * was not distributed with this source code in the LICENSE file, you can
   7  * obtain it at www.aomedia.org/license/software. If the Alliance for Open
   8  * Media Patent License 1.0 was not distributed with this source code in the
   9  * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
  10  */
  11
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <string.h>
  15
  16 #include "aom_ports/mem_ops.h"
  17
  18 #include "./ivfdec.h"
  19
  20 static const char *IVF_SIGNATURE = "DKIF";
  21
  22 static void fix_framerate(int *num, int *den) {
  23   if (*den <= 0 || *den >= 1000000000 || *num <= 0 || *num >= 1000) {
  24     // framerate seems to be invalid, just default to 30fps.
  25     *num = 30;
  26     *den = 1;
  27   }
  28 }
  29
  30 int file_is_ivf(struct AvxInputContext *input_ctx) {
  31   char raw_hdr[32];
  32   int is_ivf = 0;
  33
  34   if (fread(raw_hdr, 1, 32, input_ctx->file) == 32) {
  35     if (memcmp(IVF_SIGNATURE, raw_hdr, 4) == 0) {
  36       is_ivf = 1;
  37
  38       if (mem_get_le16(raw_hdr + 4) != 0) {
  39         fprintf(stderr,
  40                 "Error: Unrecognized IVF version! This file may not"
  41                 " decode properly.");
  42       }
  43
  44       input_ctx->fourcc = mem_get_le32(raw_hdr + 8);
  45       input_ctx->width = mem_get_le16(raw_hdr + 12);
  46       input_ctx->height = mem_get_le16(raw_hdr + 14);
  47       input_ctx->framerate.numerator = mem_get_le32(raw_hdr + 16);
  48       input_ctx->framerate.denominator = mem_get_le32(raw_hdr + 20);
  49       fix_framerate(&input_ctx->framerate.numerator,
  50                     &input_ctx->framerate.denominator);
  51     }
  52   }
  53
  54   if (!is_ivf) {
  55     rewind(input_ctx->file);
  56     input_ctx->detect.buf_read = 0;
  57   } else {
  58     input_ctx->detect.position = 4;
  59   }
  60   return is_ivf;
  61 }
  62
  63 int ivf_read_frame(FILE *infile, uint8_t **buffer, size_t *bytes_read,
  64                    size_t *buffer_size) {
  65   char raw_header[IVF_FRAME_HDR_SZ] = { 0 };
  66   size_t frame_size = 0;
  67
  68   if (fread(raw_header, IVF_FRAME_HDR_SZ, 1, infile) != 1) {
  69     if (!feof(infile)) warn("Failed to read frame size\n");
  70   } else {
  71     frame_size = mem_get_le32(raw_header);
  72
  73     if (frame_size > 256 * 1024 * 1024) {
  74       warn("Read invalid frame size (%u)\n", (unsigned int)frame_size);
  75       frame_size = 0;
  76     }
  77
  78     if (frame_size > *buffer_size) {
  79       uint8_t *new_buffer = (uint8_t *)realloc(*buffer, 2 * frame_size);
  80
  81       if (new_buffer) {
  82         *buffer = new_buffer;
  83         *buffer_size = 2 * frame_size;
  84       } else {
  85         warn("Failed to allocate compressed data buffer\n");
  86         frame_size = 0;
  87       }
  88     }
  89   }
  90
  91   if (!feof(infile)) {
  92     if (fread(*buffer, 1, frame_size, infile) != frame_size) {
  93       warn("Failed to read full frame\n");
  94       return 1;
  95     }
  96
  97     *bytes_read = frame_size;
  98     return 0;
  99   }
 100
 101   return 1;
 102 }