ApsaraVideo VOD:Advanced features

You can disable the display capability for video images to enable audio-only playback. Before you call the prepare method, configure the PlayerConfig class.

AVPConfig *config = mPlayerPtr->getConfig();
config->mDisableVideo = true;
mPlayerPtr->setConfig(config);

ApsaraVideo Player SDK for Windows supports adaptive bitrate streaming of HTTP Live Streaming (HLS) video streams and Dynamic Adaptive Streaming over HTTP (DASH) video streams. After the prepare method is called, call getMediaInfo to obtain the stream information that is indicated by TrackInfo. Sample code:

AVPMediaInfo info = mPlayerPtr->getMediaInfo();
for (int i = 0; i < info.trackCount; i++) {
     AVPTrackInfo *track = info.tracks[i];
}

During the playback, you can call selectTrack to switch to the required bitrate. If you specify SELECT_AVPTRACK_TYPE_VIDEO_AUTO in the method, adaptive bitrate streaming is enabled. Sample code:

// Switch the bitrate.
mPlayerPtr->selectTrack(trackIndex);
// Switch to the adaptive bitrate.
mPlayerPtr->selectTrack(SELECT_AVPTRACK_TYPE_VIDEO_AUTO);

The callback that is invoked by the onTrackChanged method returns the switching result. Sample code:

void AlivcLivePlayerMainDlg::onTrackChanged(AliPlayer *player, AVPTrackInfo *info)
{
    if (info->trackType == AVPTRACK_TYPE_VIDEO) {
        // video changed
    }
    // etc
}

You can call the snapShot operation to capture video snapshots. The player saves the captured snapshots in the ARGB32 format. You can obtain the information about the captured snapshots after the onSnapshotImageBuffer callback is invoked. Sample code:

// Capture a snapshot of the current video image.
mPlayerPtr->snapshot();
// Configure the callback for snapshot capture.
void AlivcLivePlayerMainDlg::onSnapshotImageBuffer(AliPlayer *player, int width, int height, unsigned char *pARGBBuffer)
{
    QString savePath = "save path";
    QImage snapshot(pARGBBuffer, width, height, QImage::Format_ARGB32);
    snapshot.save(savePath);
}

After you enable the preview feature, you can call the setPreviewTime operation in VidPlayerConfigGenerator to specify the preview duration. After you specify the preview duration, ApsaraVideo Player SDK for Windows allows you to preview a video for the specified duration instead of the whole video. The following sample code provides an example. In this example, VidSts is used.

VidPlayerConfigGenerator playConfigGen;
playConfigGen.setPreviewTime(10);
AVPVidStsSource vidSource;
vidSource.initWithVid(Video ID,
                        "accessKeyId",
                        "accessKeySecret",
                        "Security token",
                        "Access region ID",
                        playConfigGen.generatePlayerConfig());
mPlayerPtr->setSource(vidSource);

ApsaraVideo Player SDK for Windows provides the AVPConfig class for you to set the request referer. You can use the referer together with a referer whitelist or blacklist configured in the ApsaraVideo VOD console to implement access control. Sample code:

// Obtain the configuration information.
AVPConfig *pConfig = mPlayerPtr->getConfig();
// Set the referer.
pConfig->referer = referer;
....// Configure other settings.
// Configure the settings for the player.
mPlayerPtr->setConfig(pConfig);

ApsaraVideo Player SDK for Windows provides the AVPConfig class for you to specify the request user agent. After you specify the user agent, the player includes the user agent information in the requests. Sample code:

// Obtain the configuration information.
AVPConfig *pConfig = mPlayerPtr->getConfig();
// Specify the user agent.
pConfig->userAgent = userAgent;
....// Configure other settings.
// Configure the settings for the player.
mPlayerPtr->setConfig(pConfig);

ApsaraVideo Player SDK for Windows provides the AVPConfig class for you to set the network timeout period and number of retries. Sample code:

// Obtain the configuration information.
AVPConfig *pConfig = mPlayerPtr->getConfig();
// Set the network timeout period. Unit: milliseconds.
pConfig->networkTimeout = 5000;
// Specify the maximum number of retries upon a network timeout. The retry interval equals the timeout period specified by the NetworkTimeout parameter. The networkRetryCount parameter specifies the maximum number of retries. A value of 0 indicates zero retry. The application determines the maximum number of retries. Default value: 2.
pConfig->networkRetryCount = 2;
....// Configure other settings.
// Configure the settings for the player.
mPlayerPtr->setConfig(pConfig);

Buffer control is important for a player. You can reduce the startup loading duration and improve playback smoothness by using proper configurations. ApsaraVideo Player SDK for Windows provides the AVPConfig class to allow you to configure buffer settings and latency settings. Sample code:

// Obtain the configuration information.
AVPConfig *pConfig = mPlayerPtr->getConfig();
// Set the maximum latency. This parameter is valid only for live streaming. If the latency exceeds the maximum limit, ApsaraVideo Player SDK synchronizes frames to ensure that the latency does not exceed the limit. 
pConfig->maxDelayTime = 5000;
// Set the maximum buffer duration. Unit: milliseconds. This parameter specifies the maximum buffer duration for the player to load data at a time. 
pConfig->maxBufferDuration = 50000;
// Set the peak buffer duration. Unit: milliseconds. This parameter specifies the peak buffer duration. After the peak buffer duration elapses, the player stops loading data when the network conditions are poor. 
pConfig->highBufferDuration = 3000;
// Set the startup buffer duration Unit: milliseconds. A smaller value indicates a shorter startup buffer duration. In this case, the player starts to load data sooner after the playback starts. 
pConfig->startBufferDuration = 500;
// Configure other settings.
// Configure the settings for the player.
mPlayerPtr->setConfig(pConfig);

ApsaraVideo Player SDK provides the AVPConfig class for you to configure HTTP headers for the player. Sample code:

// Obtain the configuration information.
AVPConfig *pConfig = mPlayerPtr->getConfig();
// Configure the header.
pConfig->headerCount = 1;
pConfig->httpHeaders = new char *[pConfig->headerCount];
// Configure a host when you use Alibaba Cloud HTTPDNS. 
pConfig->httpHeaders[0] = strdup("Host:example.com");
....// Configure other settings.
// Configure the settings for the player.
mPlayerPtr->setConfig(pConfig);

ApsaraVideo Player SDK for Windows allows you to cache videos during playback. This saves traffic during loop playback. To configure the local caching feature, call AVPCacheConfig before you call the prepare method. Sample code:

AVPCacheConfig mCacheConfig;
// Enable the local caching feature.
mCacheConfig.enable = true;
// Specify the maximum duration of a single cached file. Files whose duration exceeds the upper limit are not cached.
mCacheConfig.maxDuration = 100;
// Specify the maximum size of the cache directory. If the total size of cached files in the cache directory exceeds the upper limit, the earliest cached files are overwritten.
mCacheConfig.maxSizeMB = 200;
// Set the cache directory to the directory required by your application.
mCacheConfig.path = strdup("please use your cache path here");
// Configure the cache settings for the player.
mPlayerPtr->setCacheConfig(&mCacheConfig);

You must call setCacheConfig to use cached files. Cached files are used in the following scenarios:

• If you enable the loop playback feature, the player automatically replays a video by using the cached video file each time the playback is complete.
• After you cache a video and create a player to play the video, the new player plays the video by using the cached video file.
  Important The player uses information such as the video ID from online requests to find cached files for video ID-based playback.

The following information describes the limits on the play-and-cache feature:

• If you use UrlSource for video playback and the playback URL is in the HLS format, the player does not cache the video during playback. If the playback URL is in other formats, the player caches videos during playback based on your configuration.
• If you use VidAuth or VidSts for playback, the player caches videos during playback based on your configuration.
• A video is cached after the player reads all video data. Caching fails if the stop method is called or the onError callback is invoked before the player reads all video data.
• In-buffer seeking does not affect the caching result. Seeking to a position outside the buffer may cause a caching failure.
• If the security file does not match the application information, the video caching fails.
• You can check the caching result from the onPlayerEvent callback. EVENT_PLAYER_CACHE_SUCCESS indicates that the video is cached and EVENT_PLAYER_CACHE_ERROR indicates that the video is not cached.

ApsaraVideo Player SDK for Windows allows you to download videos to local devices for offline playback in ApsaraVideo Player. The normal download and secure download modes are supported.

• Normal download

  Videos that are downloaded in normal download mode are not encrypted by Alibaba Cloud and can be played by third-party players.

• Secure download

  Videos that are downloaded in secure download mode are encrypted by Alibaba Cloud. You can only use ApsaraVideo Player to play these videos.