Checking in media::FFmpegGlue and some common FFmpeg code.

media/filters/ffmpeg_glue.cc

Index: media/filters/ffmpeg_glue.cc
diff --git a/media/filters/ffmpeg_glue.cc b/media/filters/ffmpeg_glue.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0d3957b527b5211c22e27cb1757189b1df970083
--- /dev/null
+++ b/media/filters/ffmpeg_glue.cc
@@ -0,0 +1,162 @@
+// Copyright (c) 2009 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.
+
+#include "base/string_util.h"
+#include "media/base/filters.h"
+#include "media/filters/ffmpeg_common.h"
+#include "media/filters/ffmpeg_glue.h"
+
+namespace {
+
+// FFmpeg protocol interface.
+int OpenContext(URLContext* h, const char* filename, int flags) {
+  scoped_refptr<media::DataSource> data_source;
+  media::FFmpegGlue::get()->GetDataSource(filename, &data_source);
+  if (!data_source)
+    return AVERROR_IO;
+
+  data_source->AddRef();
+  h->priv_data = data_source;
+  h->flags = URL_RDONLY;
+  // TODO(scherkus): data source should be able to tell us if we're streaming.
+  h->is_streamed = FALSE;
+  return 0;
+}
+
+int ReadContext(URLContext* h, unsigned char* buf, int size) {
+  media::DataSource* data_source =
+      reinterpret_cast<media::DataSource*>(h->priv_data);
+  int result = data_source->Read(buf, size);
+  if (result < 0)
+    result = AVERROR_IO;
+  return result;
+}
+
+int WriteContext(URLContext* h, unsigned char* buf, int size) {
+  // We don't support writing.
+  return AVERROR_IO;
+}
+
+offset_t SeekContext(URLContext* h, offset_t offset, int whence) {
+  media::DataSource* data_source =
+      reinterpret_cast<media::DataSource*>(h->priv_data);
+  offset_t new_offset = AVERROR_IO;
+  switch (whence) {
+    case SEEK_SET:
+      if (data_source->SetPosition(offset))
+        data_source->GetPosition(&new_offset);
+      break;
+
+    case SEEK_CUR:
+      int64 pos;
+      if (!data_source->GetPosition(&pos))
+        break;
+      if (data_source->SetPosition(pos + offset))
+        data_source->GetPosition(&new_offset);
+      break;
+
+    case SEEK_END:
+      int64 size;
+      if (!data_source->GetSize(&size))
+        break;
+      if (data_source->SetPosition(size + offset))
+        data_source->GetPosition(&new_offset);
+      break;
+
+    case AVSEEK_SIZE:
+      data_source->GetSize(&new_offset);
+      break;
+
+    default:
+      NOTREACHED();
+  }
+  if (new_offset < 0)
+    new_offset = AVERROR_IO;
+  return new_offset;
+}
+
+int CloseContext(URLContext* h) {
+  media::DataSource* data_source =
+      reinterpret_cast<media::DataSource*>(h->priv_data);
+  data_source->Release();
+  h->priv_data = NULL;
+  return 0;
+}
+
+}  // namespace
+
+//------------------------------------------------------------------------------
+
+namespace media {
+
+// Use the HTTP protocol to avoid any file path separator issues.
+static const char kProtocol[] = "http";
+
+// Fill out our FFmpeg protocol definition.
+static URLProtocol kFFmpegProtocol = {
+  kProtocol,
+  &OpenContext,
+  &ReadContext,
+  &WriteContext,
+  &SeekContext,
+  &CloseContext,
+};
+
+FFmpegGlue::FFmpegGlue() {
+  // Register our protocol glue code with FFmpeg.
+  avcodec_init();
+  register_protocol(&kFFmpegProtocol);
+
+  // Now register the rest of FFmpeg.
+  av_register_all();
+}
+
+FFmpegGlue::~FFmpegGlue() {
+  DataSourceMap::iterator iter = data_sources_.begin();
+  while (iter != data_sources_.end()) {
+    DataSource* data_source = iter->second;
+    iter = data_sources_.erase(iter);
+  }
+}
+
+std::string FFmpegGlue::AddDataSource(DataSource* data_source) {
+  AutoLock auto_lock(lock_);
+  std::string key = GetDataSourceKey(data_source);
+  if (data_sources_.find(key) == data_sources_.end()) {
+    data_sources_[key] = data_source;
+  }
+  return key;
+}
+
+void FFmpegGlue::RemoveDataSource(DataSource* data_source) {
+  AutoLock auto_lock(lock_);
+  DataSourceMap::iterator iter = data_sources_.begin();
+  while (iter != data_sources_.end()) {
+    if (iter->second == data_source) {
+      iter = data_sources_.erase(iter);
+    } else {
+      ++iter;
+    }
+  }
+}
+
+void FFmpegGlue::GetDataSource(const std::string& key,
+                               scoped_refptr<DataSource>* data_source) {
+  AutoLock auto_lock(lock_);
+  DataSourceMap::iterator iter = data_sources_.find(key);
+  if (iter == data_sources_.end()) {
+    *data_source = NULL;
+    return;
+  }
+  *data_source = iter->second;
+}
+
+std::string FFmpegGlue::GetDataSourceKey(DataSource* data_source) {
+  // Use the DataSource's memory address to generate the unique string.  This
+  // also has the nice property that adding the same DataSource reference will
+  // not generate duplicate entries.
+  return StringPrintf("%s://0x%lx", kProtocol, static_cast<void*>(data_source));
+}
+
+}  // namespace media