video_reader.c

   1 /*
   2  *  Copyright (c) 2014 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 <stdlib.h>
  12 #include <string.h>
  13
  14 #include "./ivfdec.h"
  15 #include "./video_reader.h"
  16
  17 #include "vpx_ports/mem_ops.h"
  18
  19 static const char *const kIVFSignature = "DKIF";
  20
  21 struct VpxVideoReaderStruct {
  22   VpxVideoInfo info;
  23   FILE *file;
  24   uint8_t *buffer;
  25   size_t buffer_size;
  26   size_t frame_size;
  27 };
  28
  29 VpxVideoReader *vpx_video_reader_open(const char *filename) {
  30   char header[32];
  31   VpxVideoReader *reader = NULL;
  32   FILE *const file = fopen(filename, "rb");
  33   if (!file)
  34     return NULL;  // Can't open file
  35
  36   if (fread(header, 1, 32, file) != 32)
  37     return NULL;  // Can't read file header
  38
  39   if (memcmp(kIVFSignature, header, 4) != 0)
  40     return NULL;  // Wrong IVF signature
  41
  42   if (mem_get_le16(header + 4) != 0)
  43     return NULL;  // Wrong IVF version
  44
  45   reader = calloc(1, sizeof(*reader));
  46   if (!reader)
  47     return NULL;  // Can't allocate VpxVideoReader
  48
  49   reader->file = file;
  50   reader->info.codec_fourcc = mem_get_le32(header + 8);
  51   reader->info.frame_width = mem_get_le16(header + 12);
  52   reader->info.frame_height = mem_get_le16(header + 14);
  53   reader->info.time_base.numerator = mem_get_le32(header + 16);
  54   reader->info.time_base.denominator = mem_get_le32(header + 20);
  55
  56   return reader;
  57 }
  58
  59 void vpx_video_reader_close(VpxVideoReader *reader) {
  60   if (reader) {
  61     fclose(reader->file);
  62     free(reader->buffer);
  63     free(reader);
  64   }
  65 }
  66
  67 int vpx_video_reader_read_frame(VpxVideoReader *reader) {
  68   return !ivf_read_frame(reader->file, &reader->buffer, &reader->frame_size,
  69                          &reader->buffer_size);
  70 }
  71
  72 const uint8_t *vpx_video_reader_get_frame(VpxVideoReader *reader,
  73                                           size_t *size) {
  74   if (size)
  75     *size = reader->frame_size;
  76
  77   return reader->buffer;
  78 }
  79
  80 const VpxVideoInfo *vpx_video_reader_get_info(VpxVideoReader *reader) {
  81   return &reader->info;
  82 }
  83