| /* |
| * Copyright (c) 2013 The WebM project authors. All Rights Reserved. |
| * |
| * Use of this source code is governed by a BSD-style license |
| * that can be found in the LICENSE file in the root of the source |
| * tree. An additional intellectual property rights grant can be found |
| * in the file PATENTS. All contributing project authors may |
| * be found in the AUTHORS file in the root of the source tree. |
| */ |
| |
| #include "./webmdec.h" |
| |
| #include <cstring> |
| #include <cstdio> |
| |
| #include "third_party/libwebm/mkvparser/mkvparser.h" |
| #include "third_party/libwebm/mkvparser/mkvreader.h" |
| |
| namespace { |
| |
| void reset(struct WebmInputContext *const webm_ctx) { |
| if (webm_ctx->reader != nullptr) { |
| mkvparser::MkvReader *const reader = |
| reinterpret_cast<mkvparser::MkvReader *>(webm_ctx->reader); |
| delete reader; |
| } |
| if (webm_ctx->segment != nullptr) { |
| mkvparser::Segment *const segment = |
| reinterpret_cast<mkvparser::Segment *>(webm_ctx->segment); |
| delete segment; |
| } |
| if (webm_ctx->buffer != nullptr) { |
| delete[] webm_ctx->buffer; |
| } |
| webm_ctx->reader = nullptr; |
| webm_ctx->segment = nullptr; |
| webm_ctx->buffer = nullptr; |
| webm_ctx->cluster = nullptr; |
| webm_ctx->block_entry = nullptr; |
| webm_ctx->block = nullptr; |
| webm_ctx->block_frame_index = 0; |
| webm_ctx->video_track_index = 0; |
| webm_ctx->timestamp_ns = 0; |
| webm_ctx->is_key_frame = false; |
| } |
| |
| void get_first_cluster(struct WebmInputContext *const webm_ctx) { |
| mkvparser::Segment *const segment = |
| reinterpret_cast<mkvparser::Segment *>(webm_ctx->segment); |
| const mkvparser::Cluster *const cluster = segment->GetFirst(); |
| webm_ctx->cluster = cluster; |
| } |
| |
| void rewind_and_reset(struct WebmInputContext *const webm_ctx, |
| struct VpxInputContext *const vpx_ctx) { |
| rewind(vpx_ctx->file); |
| reset(webm_ctx); |
| } |
| |
| } // namespace |
| |
| int file_is_webm(struct WebmInputContext *webm_ctx, |
| struct VpxInputContext *vpx_ctx) { |
| mkvparser::MkvReader *const reader = new mkvparser::MkvReader(vpx_ctx->file); |
| webm_ctx->reader = reader; |
| webm_ctx->reached_eos = 0; |
| |
| mkvparser::EBMLHeader header; |
| long long pos = 0; |
| if (header.Parse(reader, pos) < 0) { |
| rewind_and_reset(webm_ctx, vpx_ctx); |
| return 0; |
| } |
| |
| mkvparser::Segment *segment; |
| if (mkvparser::Segment::CreateInstance(reader, pos, segment)) { |
| rewind_and_reset(webm_ctx, vpx_ctx); |
| return 0; |
| } |
| webm_ctx->segment = segment; |
| if (segment->Load() < 0) { |
| rewind_and_reset(webm_ctx, vpx_ctx); |
| return 0; |
| } |
| |
| const mkvparser::Tracks *const tracks = segment->GetTracks(); |
| const mkvparser::VideoTrack *video_track = nullptr; |
| for (unsigned long i = 0; i < tracks->GetTracksCount(); ++i) { |
| const mkvparser::Track *const track = tracks->GetTrackByIndex(i); |
| if (track->GetType() == mkvparser::Track::kVideo) { |
| video_track = static_cast<const mkvparser::VideoTrack *>(track); |
| webm_ctx->video_track_index = static_cast<int>(track->GetNumber()); |
| break; |
| } |
| } |
| |
| if (video_track == nullptr || video_track->GetCodecId() == nullptr) { |
| rewind_and_reset(webm_ctx, vpx_ctx); |
| return 0; |
| } |
| |
| if (!strncmp(video_track->GetCodecId(), "V_VP8", 5)) { |
| vpx_ctx->fourcc = VP8_FOURCC; |
| } else if (!strncmp(video_track->GetCodecId(), "V_VP9", 5)) { |
| vpx_ctx->fourcc = VP9_FOURCC; |
| } else { |
| rewind_and_reset(webm_ctx, vpx_ctx); |
| return 0; |
| } |
| |
| vpx_ctx->framerate.denominator = 0; |
| vpx_ctx->framerate.numerator = 0; |
| vpx_ctx->width = static_cast<uint32_t>(video_track->GetWidth()); |
| vpx_ctx->height = static_cast<uint32_t>(video_track->GetHeight()); |
| |
| get_first_cluster(webm_ctx); |
| |
| return 1; |
| } |
| |
| int webm_read_frame(struct WebmInputContext *webm_ctx, uint8_t **buffer, |
| size_t *buffer_size) { |
| // This check is needed for frame parallel decoding, in which case this |
| // function could be called even after it has reached end of input stream. |
| if (webm_ctx->reached_eos) { |
| return 1; |
| } |
| mkvparser::Segment *const segment = |
| reinterpret_cast<mkvparser::Segment *>(webm_ctx->segment); |
| const mkvparser::Cluster *cluster = |
| reinterpret_cast<const mkvparser::Cluster *>(webm_ctx->cluster); |
| const mkvparser::Block *block = |
| reinterpret_cast<const mkvparser::Block *>(webm_ctx->block); |
| const mkvparser::BlockEntry *block_entry = |
| reinterpret_cast<const mkvparser::BlockEntry *>(webm_ctx->block_entry); |
| bool block_entry_eos = false; |
| do { |
| long status = 0; |
| bool get_new_block = false; |
| if (block_entry == nullptr && !block_entry_eos) { |
| status = cluster->GetFirst(block_entry); |
| get_new_block = true; |
| } else if (block_entry_eos || block_entry->EOS()) { |
| cluster = segment->GetNext(cluster); |
| if (cluster == nullptr || cluster->EOS()) { |
| *buffer_size = 0; |
| webm_ctx->reached_eos = 1; |
| return 1; |
| } |
| status = cluster->GetFirst(block_entry); |
| block_entry_eos = false; |
| get_new_block = true; |
| } else if (block == nullptr || |
| webm_ctx->block_frame_index == block->GetFrameCount() || |
| block->GetTrackNumber() != webm_ctx->video_track_index) { |
| status = cluster->GetNext(block_entry, block_entry); |
| if (block_entry == nullptr || block_entry->EOS()) { |
| block_entry_eos = true; |
| continue; |
| } |
| get_new_block = true; |
| } |
| if (status || block_entry == nullptr) { |
| return -1; |
| } |
| if (get_new_block) { |
| block = block_entry->GetBlock(); |
| if (block == nullptr) return -1; |
| webm_ctx->block_frame_index = 0; |
| } |
| } while (block_entry_eos || |
| block->GetTrackNumber() != webm_ctx->video_track_index); |
| |
| webm_ctx->cluster = cluster; |
| webm_ctx->block_entry = block_entry; |
| webm_ctx->block = block; |
| |
| const mkvparser::Block::Frame &frame = |
| block->GetFrame(webm_ctx->block_frame_index); |
| ++webm_ctx->block_frame_index; |
| if (frame.len > static_cast<long>(*buffer_size)) { |
| delete[] * buffer; |
| *buffer = new uint8_t[frame.len]; |
| if (*buffer == nullptr) { |
| return -1; |
| } |
| webm_ctx->buffer = *buffer; |
| } |
| *buffer_size = frame.len; |
| webm_ctx->timestamp_ns = block->GetTime(cluster); |
| webm_ctx->is_key_frame = block->IsKey(); |
| |
| mkvparser::MkvReader *const reader = |
| reinterpret_cast<mkvparser::MkvReader *>(webm_ctx->reader); |
| return frame.Read(reader, *buffer) ? -1 : 0; |
| } |
| |
| int webm_guess_framerate(struct WebmInputContext *webm_ctx, |
| struct VpxInputContext *vpx_ctx) { |
| uint32_t i = 0; |
| uint8_t *buffer = nullptr; |
| size_t buffer_size = 0; |
| while (webm_ctx->timestamp_ns < 1000000000 && i < 50) { |
| if (webm_read_frame(webm_ctx, &buffer, &buffer_size)) { |
| break; |
| } |
| ++i; |
| } |
| vpx_ctx->framerate.numerator = (i - 1) * 1000000; |
| vpx_ctx->framerate.denominator = |
| static_cast<int>(webm_ctx->timestamp_ns / 1000); |
| delete[] buffer; |
| // webm_ctx->buffer is assigned to the buffer pointer in webm_read_frame(). |
| webm_ctx->buffer = nullptr; |
| |
| get_first_cluster(webm_ctx); |
| webm_ctx->block = nullptr; |
| webm_ctx->block_entry = nullptr; |
| webm_ctx->block_frame_index = 0; |
| webm_ctx->timestamp_ns = 0; |
| webm_ctx->reached_eos = 0; |
| |
| return 0; |
| } |
| |
| void webm_free(struct WebmInputContext *webm_ctx) { reset(webm_ctx); } |