1 /* 2 * Copyright (c) 2013 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 "./webmdec.h" 12 13 #include <cstring> 14 #include <cstdio> 15 16 #include "third_party/libwebm/mkvparser/mkvparser.h" 17 #include "third_party/libwebm/mkvparser/mkvreader.h" 18 19 namespace { 20 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); 25 delete reader; 26 } 27 if (webm_ctx->segment != NULL) { 28 mkvparser::Segment *const segment = 29 reinterpret_cast<mkvparser::Segment *>(webm_ctx->segment); 30 delete segment; 31 } 32 if (webm_ctx->buffer != NULL) { 33 delete[] webm_ctx->buffer; 34 } 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; 45 } 46 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; 52 } 53 54 void rewind_and_reset(struct WebmInputContext *const webm_ctx, 55 struct VpxInputContext *const vpx_ctx) { 56 rewind(vpx_ctx->file); 57 reset(webm_ctx); 58 } 59 60 } // namespace 61 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; 67 68 mkvparser::EBMLHeader header; 69 long long pos = 0; 70 if (header.Parse(reader, pos) < 0) { 71 rewind_and_reset(webm_ctx, vpx_ctx); 72 return 0; 73 } 74 75 mkvparser::Segment *segment; 76 if (mkvparser::Segment::CreateInstance(reader, pos, segment)) { 77 rewind_and_reset(webm_ctx, vpx_ctx); 78 return 0; 79 } 80 webm_ctx->segment = segment; 81 if (segment->Load() < 0) { 82 rewind_and_reset(webm_ctx, vpx_ctx); 83 return 0; 84 } 85 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 = static_cast<int>(track->GetNumber()); 93 break; 94 } 95 } 96 97 if (video_track == NULL || video_track->GetCodecId() == NULL) { 98 rewind_and_reset(webm_ctx, vpx_ctx); 99 return 0; 100 } 101 102 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; 106 } else { 107 rewind_and_reset(webm_ctx, vpx_ctx); 108 return 0; 109 } 110 111 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()); 115 116 get_first_cluster(webm_ctx); 117 118 return 1; 119 } 120 121 int webm_read_frame(struct WebmInputContext *webm_ctx, uint8_t **buffer, 122 size_t *buffer_size) { 123 // This check is needed for frame parallel decoding, in which case this 124 // function could be called even after it has reached end of input stream. 125 if (webm_ctx->reached_eos) { 126 return 1; 127 } 128 mkvparser::Segment *const segment = 129 reinterpret_cast<mkvparser::Segment *>(webm_ctx->segment); 130 const mkvparser::Cluster *cluster = 131 reinterpret_cast<const mkvparser::Cluster *>(webm_ctx->cluster); 132 const mkvparser::Block *block = 133 reinterpret_cast<const mkvparser::Block *>(webm_ctx->block); 134 const mkvparser::BlockEntry *block_entry = 135 reinterpret_cast<const mkvparser::BlockEntry *>(webm_ctx->block_entry); 136 bool block_entry_eos = false; 137 do { 138 long status = 0; 139 bool get_new_block = false; 140 if (block_entry == NULL && !block_entry_eos) { 141 status = cluster->GetFirst(block_entry); 142 get_new_block = true; 143 } else if (block_entry_eos || block_entry->EOS()) { 144 cluster = segment->GetNext(cluster); 145 if (cluster == NULL || cluster->EOS()) { 146 *buffer_size = 0; 147 webm_ctx->reached_eos = 1; 148 return 1; 149 } 150 status = cluster->GetFirst(block_entry); 151 block_entry_eos = false; 152 get_new_block = true; 153 } else if (block == NULL || 154 webm_ctx->block_frame_index == block->GetFrameCount() || 155 block->GetTrackNumber() != webm_ctx->video_track_index) { 156 status = cluster->GetNext(block_entry, block_entry); 157 if (block_entry == NULL || block_entry->EOS()) { 158 block_entry_eos = true; 159 continue; 160 } 161 get_new_block = true; 162 } 163 if (status || block_entry == NULL) { 164 return -1; 165 } 166 if (get_new_block) { 167 block = block_entry->GetBlock(); 168 if (block == NULL) return -1; 169 webm_ctx->block_frame_index = 0; 170 } 171 } while (block_entry_eos || 172 block->GetTrackNumber() != webm_ctx->video_track_index); 173 174 webm_ctx->cluster = cluster; 175 webm_ctx->block_entry = block_entry; 176 webm_ctx->block = block; 177 178 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)) { 182 delete[] * buffer; 183 *buffer = new uint8_t[frame.len]; 184 if (*buffer == NULL) { 185 return -1; 186 } 187 webm_ctx->buffer = *buffer; 188 } 189 *buffer_size = frame.len; 190 webm_ctx->timestamp_ns = block->GetTime(cluster); 191 webm_ctx->is_key_frame = block->IsKey(); 192 193 mkvparser::MkvReader *const reader = 194 reinterpret_cast<mkvparser::MkvReader *>(webm_ctx->reader); 195 return frame.Read(reader, *buffer) ? -1 : 0; 196 } 197 198 int webm_guess_framerate(struct WebmInputContext *webm_ctx, 199 struct VpxInputContext *vpx_ctx) { 200 uint32_t i = 0; 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)) { 205 break; 206 } 207 ++i; 208 } 209 vpx_ctx->framerate.numerator = (i - 1) * 1000000; 210 vpx_ctx->framerate.denominator = 211 static_cast<int>(webm_ctx->timestamp_ns / 1000); 212 delete[] buffer; 213 214 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; 220 221 return 0; 222 } 223 224 void webm_free(struct WebmInputContext *webm_ctx) { reset(webm_ctx); } 225
