The tweaks configuration is used as an incubator for experimental features and also contains features implemented for specific customers that might not make it into the officially supported feature set.

Tweaks are not officially supported and are not guaranteed to be stable, i.e. their naming, functionality and API can change at any time within the tweaks or when being promoted to an official feature and moved into its final configuration namespace. Tweaks are often proof-of-concepts that are quickly implemented for urgent needs of customers. They often do not go through an architectural review and are therefore not signed and approved by the architecture team.


tweaks : {
max_buffer_level : 20,
query_parameters : {
key1: 'value1',
key2: 'value2',
mycustomname: 'another-value'
interface TweaksConfig {
    adaptation_set_switching_without_supplemental_property?: boolean;
    check_all_drm_licenses_for_kid?: boolean;
    chunked_cmaf_streaming?: boolean;
    disable_retry_for_response_status?: ResponseStatusMap;
    dword_base_media_decode_timestamps?: boolean;
    enable_seek_for_live?: boolean;
    fairplay_ignore_duplicate_init_data_key_errors?: boolean;
    force_base_media_decode_time_rewrite?: boolean;
    force_software_decryption?: boolean;
    hls_audio_only_threshold_bitrate?: number;
    hls_backup_stream_penalty_duration?: number;
    hls_clear_buffers_on_discontinuity_switches?: boolean;
    hls_parse_manifest_in_worker?: boolean;
    hls_parse_native_metadata?: boolean;
    hls_sync_segment_playback_time_via_media_sequence?: boolean;
    ignore_mp4_edts_box?: boolean;
    impressionServer?: string;
    licenseServer?: string;
    log_level?: LogLevel;
    max_buffer_level?: number;
    max_cdn_retries?: number;
    max_mpd_retries?: number;
    max_retries?: number;
    min_size_for_gap_skipping?: number;
    mpd_retry_delay?: number;
    mpd_update_period_tolerance?: number;
    native_hls_download_error_handling?: boolean;
    native_hls_parsing?: boolean;
    no_quota_exceeded_adjustment?: boolean;
    parse_cea_708_caption?: boolean;
    parse_emsg_boxes?: boolean;
    playstation_5?: PlayStation5Tweaks;
    prefer_managed_media_source?: boolean;
    preserve_gaps_for_base_media_decode_time_rewrite?: boolean;
    prevent_video_element_preloading?: boolean;
    query_parameters?: QueryParameters;
    restart_threshold?: number;
    resume_live_content_at_previous_position_after_ad_break?: boolean;
    segment_encryption_transition_handling?: boolean;
    serviceworker_scope?: string;
    startup_threshold?: number;
    stop_download_on_pause?: boolean;
    wish_abr_params?: WishAbrConfig;
    [key: string]: any;


[key: string]: any

Tweaks are meant for experimental purpose and might often change so we allow the interface to contain any option to avoid possible type checking failures.


adaptation_set_switching_without_supplemental_property?: boolean

Groups adaptation sets and switches between them based on their group attribute instead of the recommended SupplementalProperty urn:mpeg:dash:adaptation-set-switching:2016. Default is false.



check_all_drm_licenses_for_kid?: boolean

If set, the player checks all available DRM licenses when the key status for a KID updates.

Instead of surfacing an error once the KID becomes unusable on a license, the key status for the KID is checked across all licenses. Only if the KID is not usable on any of the licenses an error is thrown.

Default is true.


v8.140.2, v8.144.0

chunked_cmaf_streaming?: boolean

When set, the player will use the fetch API to download segments using HTTP chunked transfer encoding (CTE) instead of the XMLHttpRequest API. In combination with chunked CMAF content this can be used to achieve low-latency streaming.

disable_retry_for_response_status?: ResponseStatusMap

If a specific [[HttpRequestType]] has one or more HTTP status codes associated with it via this configuration value, requests of that type will not be retried if they return one of the associated status codes.




disable_retry_for_response_status: {
[HttpRequestType.MANIFEST_DASH]: [ 401 ]
dword_base_media_decode_timestamps?: boolean

If set, all BaseMediaDecodeTime-stamps will be truncated to 32 bits in length.

enable_seek_for_live?: boolean

Specifies whether seek is allowed for live streams. By default this is not allowed.

fairplay_ignore_duplicate_init_data_key_errors?: boolean

If set, keyerror events will be ignored for Fairplay when more than one needkey event was triggered with identical initData.



force_base_media_decode_time_rewrite?: boolean

If set, every BaseMediaDecodeTime in data segments will be rewritten, regardless if they exceed 32 bits or not. The tizen or webOS module has to be present and the player should run on Tizen or webOS TV.

Using this tweak might cause some unwanted problems when content has short discontinuities (e.g. SSAI streams). Enabling the tweak is only recommended when the playback experience is improved on testing.

force_software_decryption?: boolean

If set, software decryption is used over the browser's WebCrypto API for anything that the player manually decrypts. E.g. for decrypting segments of DASH ClearKey-protected and HLS AES-128-encrypted streams.

Note: Proper DRM-protection such as Widevine and PlayReady is not affected by this tweak as decryption of such must be handled by the browser's CDM.

hls_audio_only_threshold_bitrate?: number

All HLS variants with a bitrate lower than the given bitrate in bits per second (bps) are considered audio-only variants and removed if there is at least one with a higher bitrate.

hls_backup_stream_penalty_duration?: number

Defines the duration in seconds after which the backup stream penalization is considered to be expired. The penalty is applied when a playlist, or one of its segments, has failed to load, and the player has triggerd failover to a backup stream.

Default is 30 seconds.

hls_clear_buffers_on_discontinuity_switches?: boolean

When set, the SourceBuffers will be cleared between segments with different discontinuities that otherwise have matching properties. This tweak can be used to switch this behaviour off for certain streams to gain more performance and seamless playback between discontinuity boundaries.

Default is true.



hls_parse_manifest_in_worker?: boolean

When set, the player will parse the manifest in a worker thread. This can improve the performance of the player when the manifest is large.

Default is false.

hls_parse_native_metadata?: boolean

Whether the native player used for HLS on Safari should subscribe to cuechange events from the metadata TextTrack and relay ID3 events as Metadata events.

Note: This tweak has no effect if the MSE-based player (i.e. Html5) is used.

Default is true.



hls_sync_segment_playback_time_via_media_sequence?: boolean

When set, the playback times of the segments between HLS playlist are synced using media sequence number during quality switch.

Default is false.

ignore_mp4_edts_box?: boolean

If enabled, Edit (edts) boxes in MP4 segments which would introduce a segment start time offset are filtered from segments before forwarding them to the decoder. This is required as browsers are handling such boxes differently. This flag ensures consistent cross-browser behavior in this matter and is enabled by default.



impressionServer?: string

Sets the impression server to the given URL if allowlisted. Default is the bitmovin impression server URL.

licenseServer?: string

Sets the license server to the given URL if allowlisted. Default is the bitmovin license server URL.

log_level?: LogLevel

Sets the LOG_LEVEL of the player by calling setLogLevel.

max_buffer_level?: number

Changes the maximum buffer level in seconds. Default is 40 seconds. For live streams the lowest value of playlist duration for HLS, timeShiftBufferDepth for DASH and the max_buffer_level is used as a maximum value for the buffer.


Use forwardduration instead.

max_cdn_retries?: number

The number of retries per CDN if a download error occurred in VoD streams By default the player will retry 2 times.

max_mpd_retries?: number

Amount of times to retry a failed MPD download before throwing an error for failed download. By default the player will retry 2 times.

max_retries?: number

Maximum number of retries when network request fails for the provided manifest. Applies for both master and variant playlist in case of Hls.

Default value is 2.

min_size_for_gap_skipping?: number

Gaps in content that are smaller than this value will not be skipped. This tweak should be used if gap skipping is unnecessary: some browsers are able to play through small gaps in content without getting stuck.

Default value is 0, which means that all encountered gaps will be skipped.

mpd_retry_delay?: number

The time in seconds to wait before trying to download the MPD again after a download error occurred. By default the player will retry in half a second

mpd_update_period_tolerance?: number

The time in seconds that the MPD age for live streams may exceed the minimumUpdatePeriod, before it should be considered outdated. By default the player will use 5 seconds.

native_hls_download_error_handling?: boolean

If enabled the native player used for HLS in Safari would fetch and parse the HLS playlist and trigger an Error event if the download of a segment fails and the playback stalls. Default is false.

native_hls_parsing?: boolean

If enabled the native player used for HLS in Safari would fetch and parse the HLS playlist and trigger SegmentPlayback events carrying segment-specific metadata like #EXT-X-PROGRAM-DATE-TIME if present in the manifest. Default is false.

no_quota_exceeded_adjustment?: boolean

Specifies whether the Player should not adjust the target buffer levels after a QuotaExceededError.



parse_cea_708_caption?: boolean

When set, CEA-708 captions are parsed when present in the source stream, instead of CEA-608. By default CEA-608 captions are parsed.

parse_emsg_boxes?: boolean

Whether the player should parse and process emsg boxes from MP4 segments.

Note: This tweak is limited to the MSE-based player (i.e. if getPlayerType returns Html5) and has no effect for the native player (Native).

Default is true.



playstation_5?: PlayStation5Tweaks

PlayStation 5 Platform tweaks

prefer_managed_media_source?: boolean

Use ManagedMediaSource over regular MediaSource when both are available.

Default is true.

preserve_gaps_for_base_media_decode_time_rewrite?: boolean

If set to true, the BMDT will preserve possible gaps in segments while rewriting timestamps, which may prevent out of sync audio and video.

prevent_video_element_preloading?: boolean

This flag indicates whether we prevent the native video element to preload data. Metadata will always be preloaded. In case of native HLS playback on Safari, this will cause e.g. AudioTracks not being added, before the playback starts.

query_parameters?: QueryParameters

Query parameters are added as GET parameters to all request URLs (e.g. manifest, media segments, subtitle files, …). Query_parameters should be an object with key value pairs, where the keys are used as parameter name and the values as parameter values.


query_parameters : {
key1: 'value1',
key2: 'value2',
mycustomname: 'another-value'

The example above would be translated into MY_REQUEST_URL?key1=value1&key2=value2&mycustomname=another-value.

restart_threshold?: number

Amount of seconds the player buffers before playback starts again after a stall. Default is 0.9 seconds. This value is restricted to the maximum value of the buffer minus 0.5 seconds.

resume_live_content_at_previous_position_after_ad_break?: boolean

Specifies whether live content should resume playback at the playback time before the ad break. This is required in order to be able to use replaceContentDuration for live streams. By default, live content resumes at the live edge. Note: enable_seek_for_live is required if this is set to true.



segment_encryption_transition_handling?: boolean

Makes sure that player initialize period switch and recreate source buffers in case that we are switching from unenctyped to encrypted segments. This fixes the issues with pixelated picture on playready protected HLS stream with unecrypted SSAI in MS Edge.


As of 8.33.0 new buffer handling covers this case by default so it doesn't have any effect.



serviceworker_scope?: string

Defines the scope of the ServiceWorker that is created in the bitmovin-serviceworker-client.js module.



startup_threshold?: number

Amount of seconds the player buffers before playback starts. Default is 0.9 seconds. This value is restricted to the maximum value of the buffer minus 0.5 seconds.

stop_download_on_pause?: boolean

Enabling this flag prevents the player from downloading any further resource (playlist, segments, ...), when the player is paused. Already issued requests will be finished. Default is false.

wish_abr_params?: WishAbrConfig

Configuration options for WISH ABR logic. You can enable the logic by setting logic to WISH.