webmdec.h

   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 #ifndef WEBMDEC_H_
  12 #define WEBMDEC_H_
  13
  14 #include "./tools_common.h"
  15
  16 #ifdef __cplusplus
  17 extern "C" {
  18 #endif
  19
  20 struct AvxInputContext;
  21
  22 struct WebmInputContext {
  23   void *reader;
  24   void *segment;
  25   uint8_t *buffer;
  26   const void *cluster;
  27   const void *block_entry;
  28   const void *block;
  29   int block_frame_index;
  30   int video_track_index;
  31   uint64_t timestamp_ns;
  32   int is_key_frame;
  33   int reached_eos;
  34 };
  35
  36 // Checks if the input is a WebM file. If so, initializes WebMInputContext so
  37 // that webm_read_frame can be called to retrieve a video frame.
  38 // Returns 1 on success and 0 on failure or input is not WebM file.
  39 // TODO(vigneshv): Refactor this function into two smaller functions specific
  40 // to their task.
  41 int file_is_webm(struct WebmInputContext *webm_ctx,
  42                  struct AvxInputContext *aom_ctx);
  43
  44 // Reads a WebM Video Frame. Memory for the buffer is created, owned and managed
  45 // by this function. For the first call, |buffer| should be NULL and
  46 // |*buffer_size| should be 0. Once all the frames are read and used,
  47 // webm_free() should be called, otherwise there will be a leak.
  48 // Parameters:
  49 //      webm_ctx - WebmInputContext object
  50 //      buffer - pointer where the frame data will be filled.
  51 //      buffer_size - pointer to buffer size.
  52 // Return values:
  53 //      0 - Success
  54 //      1 - End of Stream
  55 //     -1 - Error
  56 int webm_read_frame(struct WebmInputContext *webm_ctx, uint8_t **buffer,
  57                     size_t *buffer_size);
  58
  59 // Guesses the frame rate of the input file based on the container timestamps.
  60 int webm_guess_framerate(struct WebmInputContext *webm_ctx,
  61                          struct AvxInputContext *aom_ctx);
  62
  63 // Resets the WebMInputContext.
  64 void webm_free(struct WebmInputContext *webm_ctx);
  65
  66 #ifdef __cplusplus
  67 }  // extern "C"
  68 #endif
  69
  70 #endif  // WEBMDEC_H_