1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
|
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef MEDIA_WEBM_CHROMEOS_WEBM_ENCODER_H_
#define MEDIA_WEBM_CHROMEOS_WEBM_ENCODER_H_
#include <stack>
#include <stdio.h>
#include "base/file_path.h"
#include "media/base/media_export.h"
#include "media/webm/chromeos/ebml_writer.h"
extern "C" {
#define VPX_CODEC_DISABLE_COMPAT 1
#include "third_party/libvpx/source/libvpx/vpx/vpx_encoder.h"
#include "third_party/libvpx/source/libvpx/vpx/vp8cx.h"
}
class FilePath;
class SkBitmap;
namespace media {
namespace chromeos {
// WebM encoder using libvpx. Currently only supports one-pass, constant bitrate
// encoding of short files consisting of a single video track. Seek info and
// cues are not supported, so generated .webm file does not strictly adhere to
// WebM standard (http://www.webmproject.org/code/specs/container/).
class MEDIA_EXPORT WebmEncoder {
public:
// Create new instance for writing to |output_path|. If |realtime| is |true|,
// uses realtime deadline, otherwise - "good quality" deadline.
WebmEncoder(const FilePath& output_path, int bitrate, bool realtime);
~WebmEncoder();
// Encodes video from a Nx(N*M) sprite, having M frames of size NxN with FPS
// |fps_n/fps_d|. Must be called on a thread that allows disk IO.
// Returns |true| iff encoding and writing to file is successful.
bool EncodeFromSprite(const SkBitmap& sprite, int fps_n, int fps_d);
private:
// Writes global WebM header and starts a single video track. Returns |false|
// if there was an error opening file for writing.
bool WriteWebmHeader();
// Writes VPX packet to output file.
void WriteWebmBlock(const vpx_codec_cx_pkt_t* packet);
// Finishes video track and closes output file. Returns |false| if there were
// any error during encoding/writing file.
bool WriteWebmFooter();
// Starts a new WebM sub-element of given type. Those can be nested.
void StartSubElement(unsigned long class_id);
// Closes current top-level sub-element.
void EndSubElement();
// libmkv callbacks.
void EbmlWrite(const void* buffer, unsigned long len);
void EbmlSerialize(const void* buffer, int buffer_size, unsigned long len);
template <typename T>
void EbmlSerializeHelper(const T* buffer, unsigned long len);
// Video dimensions and FPS.
size_t width_;
size_t height_;
vpx_rational_t fps_;
// Number of frames in video.
size_t frame_count_;
// VPX config in use.
vpx_codec_enc_cfg_t config_;
// VPX parameters.
int bitrate_;
unsigned long deadline_;
// EbmlWriter context.
EbmlGlobal ebml_writer_;
// Stack with start offsets of currently open sub-elements.
std::stack<long int> ebml_sub_elements_;
FilePath output_path_;
FILE* output_;
// True if an error occured while encoding/writing to file.
bool has_errors_;
DISALLOW_COPY_AND_ASSIGN(WebmEncoder);
};
} // namespace chromeos
} // namespace media
#endif // MEDIA_WEBM_CHROMEOS_WEBM_ENCODER_H_
|
