1// Copyright 2013 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "media/base/media_file_checker.h"
6
7#include <map>
8
9#include "base/bind.h"
10#include "base/time/time.h"
11#include "media/ffmpeg/ffmpeg_common.h"
12#include "media/filters/blocking_url_protocol.h"
13#include "media/filters/ffmpeg_glue.h"
14#include "media/filters/file_data_source.h"
15
16namespace media {
17
18static const int64 kMaxCheckTimeInSeconds = 5;
19
20static void OnError(bool* called) {
21  *called = false;
22}
23
24MediaFileChecker::MediaFileChecker(base::File file) : file_(file.Pass()) {
25}
26
27MediaFileChecker::~MediaFileChecker() {
28}
29
30bool MediaFileChecker::Start(base::TimeDelta check_time) {
31  media::FileDataSource source(file_.Pass());
32  bool read_ok = true;
33  media::BlockingUrlProtocol protocol(&source, base::Bind(&OnError, &read_ok));
34  media::FFmpegGlue glue(&protocol);
35  AVFormatContext* format_context = glue.format_context();
36
37  if (!glue.OpenContext())
38    return false;
39
40  if (avformat_find_stream_info(format_context, NULL) < 0)
41    return false;
42
43  // Remember the codec context for any decodable audio or video streams.
44  std::map<int, AVCodecContext*> stream_contexts;
45  for (size_t i = 0; i < format_context->nb_streams; ++i) {
46    AVCodecContext* c = format_context->streams[i]->codec;
47    if (c->codec_type == AVMEDIA_TYPE_AUDIO ||
48        c->codec_type == AVMEDIA_TYPE_VIDEO) {
49      AVCodec* codec = avcodec_find_decoder(c->codec_id);
50      if (codec && avcodec_open2(c, codec, NULL) >= 0)
51        stream_contexts[i] = c;
52    }
53  }
54
55  if (stream_contexts.size() == 0)
56    return false;
57
58  AVPacket packet;
59  scoped_ptr<AVFrame, media::ScopedPtrAVFreeFrame> frame(av_frame_alloc());
60  int result = 0;
61
62  const base::TimeTicks deadline = base::TimeTicks::Now() +
63      std::min(check_time,
64               base::TimeDelta::FromSeconds(kMaxCheckTimeInSeconds));
65  do {
66    result = av_read_frame(glue.format_context(), &packet);
67    if (result < 0)
68      break;
69    result = av_dup_packet(&packet);
70    if (result < 0)
71      break;
72
73    std::map<int, AVCodecContext*>::const_iterator it =
74        stream_contexts.find(packet.stream_index);
75    if (it == stream_contexts.end()) {
76      av_free_packet(&packet);
77      continue;
78    }
79    AVCodecContext* av_context = it->second;
80
81    int frame_decoded = 0;
82    if (av_context->codec_type == AVMEDIA_TYPE_AUDIO) {
83      // A shallow copy of packet so we can slide packet.data as frames are
84      // decoded; otherwise av_free_packet() will corrupt memory.
85      AVPacket temp_packet = packet;
86      do {
87        result = avcodec_decode_audio4(av_context, frame.get(), &frame_decoded,
88                                       &temp_packet);
89        if (result < 0)
90          break;
91        av_frame_unref(frame.get());
92        temp_packet.size -= result;
93        temp_packet.data += result;
94        frame_decoded = 0;
95      } while (temp_packet.size > 0);
96    } else if (av_context->codec_type == AVMEDIA_TYPE_VIDEO) {
97      result = avcodec_decode_video2(av_context, frame.get(), &frame_decoded,
98                                     &packet);
99      if (result >= 0 && frame_decoded)
100        av_frame_unref(frame.get());
101    }
102    av_free_packet(&packet);
103  } while (base::TimeTicks::Now() < deadline && read_ok && result >= 0);
104
105  return read_ok && (result == AVERROR_EOF || result >= 0);
106}
107
108}  // namespace media
109