BASS_WEBM_StreamCreateFile

Creates a sample stream from a WebM or Matroska file.

HSTREAM BASS_WEBM_StreamCreateFile(
    DWORD filetype,
    void *file,
    QWORD offset,
    QWORD length,
    DWORD flags,
    DWORD track
);

Parameters

filetypeOne of the following.
BASS_FILE_NAMEfile is a filename. This is the default if none is specified.
BASS_FILE_MEMfile points to a memory block, which will be read from directly, so it needs to stay valid for the lifetime of the stream.
BASS_FILE_MEMCOPYfile points to a memory block, which will be copied, so it does not need to stay valid beyond this function call. This requires BASS 2.4.18 or above.
BASS_FILE_HANDLEfile is a file handle (HANDLE) on Windows or a file descriptor (int) on other platforms, and should be seekable. It will be duplicated, so the original can be closed whenever wanted but it should not be used to access the file while the stream is. This requires BASS 2.4.18 or above.
fileThe file as described by filetype.
offsetFile offset to begin reading from.
lengthMaximum read length... 0 = to the end of the file.
flagsA combination of these flags.
BASS_SAMPLE_FLOATUse 32-bit floating-point sample data. See Floating-point channels for info.
BASS_SAMPLE_3DEnable 3D functionality. The stream must be mono. The SPEAKER flags cannot be used together with this flag.
BASS_SAMPLE_LOOPLoop the file. This flag can be toggled at any time using BASS_ChannelFlags.
BASS_STREAM_AUTOFREEAutomatically free the stream when playback ends.
BASS_STREAM_DECODEDecode the sample data, without playing it. Use BASS_ChannelGetData to retrieve decoded sample data. The BASS_SAMPLE_3D, BASS_STREAM_AUTOFREE and SPEAKER flags cannot be used together with this flag.
BASS_SPEAKER_xxxSpeaker assignment flags. These flags have no effect when the stream is more than stereo.
BASS_ASYNCFILERead the file asynchronously. When enabled, the file is read and buffered in parallel with the decoding, to reduce the chances of the decoder being affected by I/O delays. This can be particularly useful with slow storage media and/or low latency output. The size of the file buffer is determined by the BASS_CONFIG_ASYNCFILE_BUFFER config option. This flag is ignored when streaming from memory.
BASS_UNICODEfile is in UTF-16 form. Otherwise it is ANSI on Windows and UTF-8 on other platforms. This flag is ignored when file is not a filename.
trackThe track to play from the file... 1 = first, 0 = first playable track. When requesting the first playable track, all tracks will be checked in numerical order until a playable one is found. The active track is available via the BASS_ATTRIB_WEBM_TRACK attribute.

Return value

If successful, the new stream's handle is returned, else 0 is returned. Use BASS_ErrorGetCode to get the error code.

Error codes

BASS_ERROR_INITBASS_Init has not been successfully called.
BASS_ERROR_NOTAVAILThe BASS_STREAM_AUTOFREE flag cannot be combined with the BASS_STREAM_DECODE flag.
BASS_ERROR_ILLPARAMfiletype and/or length is invalid. length cannot be 0 when streaming from memory.
BASS_ERROR_FILEOPENThe file could not be opened.
BASS_ERROR_FILEFORMThe file's format is not recognised/supported.
BASS_ERROR_NOTAUDIOThe track or file does not contain audio.
BASS_ERROR_CODECThe file uses a codec that is not available/supported.
BASS_ERROR_FORMATThe sample format is not supported.
BASS_ERROR_SPEAKERThe specified SPEAKER flags are invalid.
BASS_ERROR_MEMThere is insufficent memory.
BASS_ERROR_NO3DCould not initialize 3D support.
BASS_ERROR_WEBM_TRACKtrack is invalid.
BASS_ERROR_UNKNOWNSome other mystery problem!

Remarks

WebM is a subset of the Matroska file format. WebM files can contain Vorbis or Opus audio data, while Matroska also supports other codecs including AAC / AC3 / MP3. BASS includes support for Vorbis and MP3, and AAC on some platforms, but add-ons are required (loaded via BASS_PluginLoad) to support other codecs, eg. BASSOPUS for Opus. Not all Matroska features are supported but most Matroska files should be playable.

When using the plugin system, the availability of the BASS_ATTRIB_WEBM_TRACK attribute can be used to identify a WebM or Matroska file. The stream's ctype value from BASS_ChannelGetInfo tells the format of the active track from the file.

WebM and Matroska files can have tags for the file as a whole and for individual tracks. When present, they are available as a series of null-terminated UTF-8 strings from BASS_ChannelGetTags with BASS_TAG_WEBM and BASS_TAG_WEBM_TRACK, respectively. In the case of BASS_TAG_WEBM_TRACK, the active track's tags are given. When the Vorbis codec is used, BASS_TAG_OGG tags may also be available.

See also

BASS_WEBM_StreamCreateFileUser, BASS_WEBM_StreamCreateURL

BASS_ChannelGetInfo, BASS_ChannelGetLength, BASS_ChannelGetTags, BASS_ChannelPlay, BASS_ChannelSetAttribute, BASS_ChannelSetDSP, BASS_ChannelSetFX, BASS_StreamFree, BASS_StreamGetFilePosition