2 * Copyright (c) 2013 The WebM project authors. All Rights Reserved.
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.
11 #include "./webmdec.h"
16 #include "third_party/libwebm/mkvparser/mkvparser.h"
17 #include "third_party/libwebm/mkvparser/mkvreader.h"
21 void reset(struct WebmInputContext *const webm_ctx) {
22 if (webm_ctx->reader != NULL) {
23 mkvparser::MkvReader *const reader =
24 reinterpret_cast<mkvparser::MkvReader*>(webm_ctx->reader);
27 if (webm_ctx->segment != NULL) {
28 mkvparser::Segment *const segment =
29 reinterpret_cast<mkvparser::Segment*>(webm_ctx->segment);
32 if (webm_ctx->buffer != NULL) {
33 delete[] webm_ctx->buffer;
35 webm_ctx->reader = NULL;
36 webm_ctx->segment = NULL;
37 webm_ctx->buffer = NULL;
38 webm_ctx->cluster = NULL;
39 webm_ctx->block_entry = NULL;
40 webm_ctx->block = NULL;
41 webm_ctx->block_frame_index = 0;
42 webm_ctx->video_track_index = 0;
43 webm_ctx->timestamp_ns = 0;
44 webm_ctx->is_key_frame = false;
47 void get_first_cluster(struct WebmInputContext *const webm_ctx) {
48 mkvparser::Segment *const segment =
49 reinterpret_cast<mkvparser::Segment*>(webm_ctx->segment);
50 const mkvparser::Cluster *const cluster = segment->GetFirst();
51 webm_ctx->cluster = cluster;
54 void rewind_and_reset(struct WebmInputContext *const webm_ctx,
55 struct VpxInputContext *const vpx_ctx) {
56 rewind(vpx_ctx->file);
62 int file_is_webm(struct WebmInputContext *webm_ctx,
63 struct VpxInputContext *vpx_ctx) {
64 mkvparser::MkvReader *const reader = new mkvparser::MkvReader(vpx_ctx->file);
65 webm_ctx->reader = reader;
66 webm_ctx->reached_eos = 0;
68 mkvparser::EBMLHeader header;
70 if (header.Parse(reader, pos) < 0) {
71 rewind_and_reset(webm_ctx, vpx_ctx);
75 mkvparser::Segment* segment;
76 if (mkvparser::Segment::CreateInstance(reader, pos, segment)) {
77 rewind_and_reset(webm_ctx, vpx_ctx);
80 webm_ctx->segment = segment;
81 if (segment->Load() < 0) {
82 rewind_and_reset(webm_ctx, vpx_ctx);
86 const mkvparser::Tracks *const tracks = segment->GetTracks();
87 const mkvparser::VideoTrack* video_track = NULL;
88 for (unsigned long i = 0; i < tracks->GetTracksCount(); ++i) {
89 const mkvparser::Track* const track = tracks->GetTrackByIndex(i);
90 if (track->GetType() == mkvparser::Track::kVideo) {
91 video_track = static_cast<const mkvparser::VideoTrack*>(track);
92 webm_ctx->video_track_index = track->GetNumber();
97 if (video_track == NULL || video_track->GetCodecId() == NULL) {
98 rewind_and_reset(webm_ctx, vpx_ctx);
102 if (!strncmp(video_track->GetCodecId(), "V_VP8", 5)) {
103 vpx_ctx->fourcc = VP8_FOURCC;
104 } else if (!strncmp(video_track->GetCodecId(), "V_VP9", 5)) {
105 vpx_ctx->fourcc = VP9_FOURCC;
107 rewind_and_reset(webm_ctx, vpx_ctx);
111 vpx_ctx->framerate.denominator = 0;
112 vpx_ctx->framerate.numerator = 0;
113 vpx_ctx->width = static_cast<uint32_t>(video_track->GetWidth());
114 vpx_ctx->height = static_cast<uint32_t>(video_track->GetHeight());
116 get_first_cluster(webm_ctx);
121 int webm_read_frame(struct WebmInputContext *webm_ctx,
123 size_t *buffer_size) {
124 // This check is needed for frame parallel decoding, in which case this
125 // function could be called even after it has reached end of input stream.
126 if (webm_ctx->reached_eos) {
129 mkvparser::Segment *const segment =
130 reinterpret_cast<mkvparser::Segment*>(webm_ctx->segment);
131 const mkvparser::Cluster* cluster =
132 reinterpret_cast<const mkvparser::Cluster*>(webm_ctx->cluster);
133 const mkvparser::Block *block =
134 reinterpret_cast<const mkvparser::Block*>(webm_ctx->block);
135 const mkvparser::BlockEntry *block_entry =
136 reinterpret_cast<const mkvparser::BlockEntry*>(webm_ctx->block_entry);
137 bool block_entry_eos = false;
140 bool get_new_block = false;
141 if (block_entry == NULL && !block_entry_eos) {
142 status = cluster->GetFirst(block_entry);
143 get_new_block = true;
144 } else if (block_entry_eos || block_entry->EOS()) {
145 cluster = segment->GetNext(cluster);
146 if (cluster == NULL || cluster->EOS()) {
148 webm_ctx->reached_eos = 1;
151 status = cluster->GetFirst(block_entry);
152 block_entry_eos = false;
153 get_new_block = true;
154 } else if (block == NULL ||
155 webm_ctx->block_frame_index == block->GetFrameCount() ||
156 block->GetTrackNumber() != webm_ctx->video_track_index) {
157 status = cluster->GetNext(block_entry, block_entry);
158 if (block_entry == NULL || block_entry->EOS()) {
159 block_entry_eos = true;
162 get_new_block = true;
164 if (status || block_entry == NULL) {
168 block = block_entry->GetBlock();
169 webm_ctx->block_frame_index = 0;
171 } while (block->GetTrackNumber() != webm_ctx->video_track_index ||
174 webm_ctx->cluster = cluster;
175 webm_ctx->block_entry = block_entry;
176 webm_ctx->block = block;
178 const mkvparser::Block::Frame& frame =
179 block->GetFrame(webm_ctx->block_frame_index);
180 ++webm_ctx->block_frame_index;
181 if (frame.len > static_cast<long>(*buffer_size)) {
183 *buffer = new uint8_t[frame.len];
184 if (*buffer == NULL) {
187 webm_ctx->buffer = *buffer;
189 *buffer_size = frame.len;
190 webm_ctx->timestamp_ns = block->GetTime(cluster);
191 webm_ctx->is_key_frame = block->IsKey();
193 mkvparser::MkvReader *const reader =
194 reinterpret_cast<mkvparser::MkvReader*>(webm_ctx->reader);
195 return frame.Read(reader, *buffer) ? -1 : 0;
198 int webm_guess_framerate(struct WebmInputContext *webm_ctx,
199 struct VpxInputContext *vpx_ctx) {
201 uint8_t *buffer = NULL;
202 size_t buffer_size = 0;
203 while (webm_ctx->timestamp_ns < 1000000000 && i < 50) {
204 if (webm_read_frame(webm_ctx, &buffer, &buffer_size)) {
209 vpx_ctx->framerate.numerator = (i - 1) * 1000000;
210 vpx_ctx->framerate.denominator =
211 static_cast<int>(webm_ctx->timestamp_ns / 1000);
214 get_first_cluster(webm_ctx);
215 webm_ctx->block = NULL;
216 webm_ctx->block_entry = NULL;
217 webm_ctx->block_frame_index = 0;
218 webm_ctx->timestamp_ns = 0;
219 webm_ctx->reached_eos = 0;
224 void webm_free(struct WebmInputContext *webm_ctx) {