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
16 namespace media {
17
18 static const int64 kMaxCheckTimeInSeconds = 5;
19
OnError(bool * called)20 static void OnError(bool* called) {
21 *called = false;
22 }
23
MediaFileChecker(const base::PlatformFile & file)24 MediaFileChecker::MediaFileChecker(const base::PlatformFile& file)
25 : file_(file),
26 file_closer_(&file_) {
27 }
28
~MediaFileChecker()29 MediaFileChecker::~MediaFileChecker() {
30 }
31
Start(base::TimeDelta check_time)32 bool MediaFileChecker::Start(base::TimeDelta check_time) {
33 media::FileDataSource source;
34 bool read_ok = true;
35 media::BlockingUrlProtocol protocol(&source, base::Bind(&OnError, &read_ok));
36 media::FFmpegGlue glue(&protocol);
37 source.InitializeFromPlatformFile(file_);
38 AVFormatContext* format_context = glue.format_context();
39
40 if (!glue.OpenContext())
41 return false;
42
43 if (avformat_find_stream_info(format_context, NULL) < 0)
44 return false;
45
46 // Remember the codec context for any decodable audio or video streams.
47 std::map<int, AVCodecContext*> stream_contexts;
48 for (size_t i = 0; i < format_context->nb_streams; ++i) {
49 AVCodecContext* c = format_context->streams[i]->codec;
50 if (c->codec_type == AVMEDIA_TYPE_AUDIO ||
51 c->codec_type == AVMEDIA_TYPE_VIDEO) {
52 AVCodec* codec = avcodec_find_decoder(c->codec_id);
53 if (codec && avcodec_open2(c, codec, NULL) >= 0)
54 stream_contexts[i] = c;
55 }
56 }
57
58 if (stream_contexts.size() == 0)
59 return false;
60
61 AVPacket packet;
62 scoped_ptr_malloc<AVFrame, media::ScopedPtrAVFreeFrame> frame(
63 av_frame_alloc());
64 int result = 0;
65
66 base::Time deadline = base::Time::Now() +
67 std::min(check_time,
68 base::TimeDelta::FromSeconds(kMaxCheckTimeInSeconds));
69 do {
70 result = av_read_frame(glue.format_context(), &packet);
71 if (result < 0)
72 break;
73 result = av_dup_packet(&packet);
74 if (result < 0)
75 break;
76
77 std::map<int, AVCodecContext*>::const_iterator it =
78 stream_contexts.find(packet.stream_index);
79 if (it == stream_contexts.end()) {
80 av_free_packet(&packet);
81 continue;
82 }
83 AVCodecContext* av_context = it->second;
84
85 int frame_decoded = 0;
86 if (av_context->codec_type == AVMEDIA_TYPE_AUDIO) {
87 // A shallow copy of packet so we can slide packet.data as frames are
88 // decoded; otherwise av_free_packet() will corrupt memory.
89 AVPacket temp_packet = packet;
90 do {
91 avcodec_get_frame_defaults(frame.get());
92 result = avcodec_decode_audio4(av_context, frame.get(), &frame_decoded,
93 &temp_packet);
94 if (result < 0)
95 break;
96 temp_packet.size -= result;
97 temp_packet.data += result;
98 } while (temp_packet.size > 0);
99 } else if (av_context->codec_type == AVMEDIA_TYPE_VIDEO) {
100 avcodec_get_frame_defaults(frame.get());
101 result = avcodec_decode_video2(av_context, frame.get(), &frame_decoded,
102 &packet);
103 }
104 av_free_packet(&packet);
105 } while (base::Time::Now() < deadline && read_ok && result >= 0);
106
107 return read_ok && (result == AVERROR_EOF || result >= 0);
108 }
109
110 } // namespace media
111