Add media file validation to utility process

media/base/media_file_checker.cc

+// Copyright 2013 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 "media/base/media_file_checker.h"
+
+#include <map>
+
+#include "base/bind.h"
+#include "base/time/time.h"
+#include "media/ffmpeg/ffmpeg_common.h"
+#include "media/filters/blocking_url_protocol.h"
+#include "media/filters/ffmpeg_glue.h"
+#include "media/filters/file_data_source.h"
+
+namespace media {
+
+namespace {

[DaleCurtis, 2013/08/09 00:58:04]

media codebase prefers static to unnamed namespace.

[vandebo (ex-Chrome), 2013/08/09 04:26:14]

But static is deprecated in namespace scope... Done.

+
+const int64 kMaxCheckTimeInSeconds = 5;
+
+void OnError(bool* called) {
+  *called = false;
+}
+
+}  // namespace
+
+MediaFileChecker::MediaFileChecker(const base::PlatformFile& file)
+    : file_(file),
+      file_closer_(&file_) {
+}
+
+MediaFileChecker::~MediaFileChecker() {
+}
+
+bool MediaFileChecker::Start(base::TimeDelta check_time) {
+  media::FileDataSource source;
+  bool read_ok = true;
+  media::BlockingUrlProtocol protocol(&source, base::Bind(&OnError, &read_ok));
+  media::FFmpegGlue glue(&protocol);
+  source.InitializeFromPlatformFile(file_);
+  AVFormatContext* format_context = glue.format_context();
+
+  if (!glue.OpenContext())
+    return false;
+
+  if (avformat_find_stream_info(format_context, NULL) < 0)
+    return false;
+
+  // Remember the codec context for any decodable audio or video streams.
+  std::map<int, AVCodecContext*> stream_contexts;
+  for (size_t i = 0; i < format_context->nb_streams; ++i) {
+    AVCodecContext* c = format_context->streams[i]->codec;
+    if (c->codec_type == AVMEDIA_TYPE_AUDIO ||
+        c->codec_type == AVMEDIA_TYPE_VIDEO) {
+      AVCodec* codec = avcodec_find_decoder(c->codec_id);
+      if (codec && avcodec_open2(c, codec, NULL) >= 0) {

[DaleCurtis, 2013/08/09 00:58:04]

No {} to keep style w/ rest of file.

[vandebo (ex-Chrome), 2013/08/09 04:26:14]

Oops, Done.

+        stream_contexts[i] = c;
+      }
+    }
+  }
+
+  if (stream_contexts.size() == 0)
+    return false;
+
+  AVPacket packet;
+  scoped_ptr_malloc<AVFrame, media::ScopedPtrAVFree> frame(
+      avcodec_alloc_frame());
+  int result = 0;
+
+  base::Time deadline = base::Time::Now() +
+      std::min(check_time,
+               base::TimeDelta::FromSeconds(kMaxCheckTimeInSeconds));
+  do {
+    result = av_read_frame(glue.format_context(), &packet);
+    if (result < 0)
+      break;
+    result = av_dup_packet(&packet);
+    if (result < 0)
+      break;
+
+    std::map<int, AVCodecContext*>::const_iterator it =
+        stream_contexts.find(packet.stream_index);
+    if (it == stream_contexts.end()) {
+      av_free_packet(&packet);
+      continue;
+    }
+    AVCodecContext* av_context = it->second;
+
+    int frame_decoded = 0;
+    if (av_context->codec_type == AVMEDIA_TYPE_AUDIO) {
+      // A shallow copy of packet so we can slide packet.data as frames are
+      // decoded; otherwise av_free_packet() will corrupt memory.
+      AVPacket temp_packet = packet;
+      do {
+        avcodec_get_frame_defaults(frame.get());
+        result = avcodec_decode_audio4(av_context, frame.get(), &frame_decoded,
+                                       &temp_packet);
+        if (result < 0)
+          break;
+        temp_packet.size -= result;
+        temp_packet.data += result;
+      } while (temp_packet.size > 0);
+    } else if (av_context->codec_type == AVMEDIA_TYPE_VIDEO) {
+      avcodec_get_frame_defaults(frame.get());
+      result = avcodec_decode_video2(av_context, frame.get(), &frame_decoded,
+                                     &packet);
+    }
+    av_free_packet(&packet);
+  } while (base::Time::Now() < deadline && read_ok && result >= 0);
+
+  return read_ok && (result == AVERROR_EOF || result >= 0);
+}
+
+}  // namespace media