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
| filetype | One of the following.
| BASS_FILE_NAME | file is a filename. This is the default if none is specified.
| | BASS_FILE_MEM | file 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_MEMCOPY | file 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_HANDLE | file 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.
|
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| file | The file as described by filetype.
|
| offset | File offset to begin reading from.
|
| length | Maximum read length... 0 = to the end of the file.
|
| flags | A combination of these flags.
| BASS_SAMPLE_FLOAT | Use 32-bit floating-point sample data. See Floating-point channels for info.
| | BASS_SAMPLE_3D | Enable 3D functionality. The stream must be mono. The SPEAKER flags cannot be used together with this flag.
| | BASS_SAMPLE_LOOP | Loop the file. This flag can be toggled at any time using BASS_ChannelFlags.
| | BASS_STREAM_AUTOFREE | Automatically free the stream when playback ends.
| | BASS_STREAM_DECODE | Decode 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_xxx | Speaker assignment flags. These flags have no effect when the stream is more than stereo.
| | BASS_ASYNCFILE | Read 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_UNICODE | file 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.
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| track | The 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_INIT | BASS_Init has not been successfully called.
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| BASS_ERROR_NOTAVAIL | The BASS_STREAM_AUTOFREE flag cannot be combined with the BASS_STREAM_DECODE flag.
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| BASS_ERROR_ILLPARAM | filetype and/or length is invalid. length cannot be 0 when streaming from memory.
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| BASS_ERROR_FILEOPEN | The file could not be opened.
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| BASS_ERROR_FILEFORM | The file's format is not recognised/supported.
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| BASS_ERROR_NOTAUDIO | The track or file does not contain audio.
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| BASS_ERROR_CODEC | The file uses a codec that is not available/supported.
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| BASS_ERROR_FORMAT | The sample format is not supported.
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| BASS_ERROR_SPEAKER | The specified SPEAKER flags are invalid.
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| BASS_ERROR_MEM | There is insufficent memory.
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| BASS_ERROR_NO3D | Could not initialize 3D support.
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| BASS_ERROR_WEBM_TRACK | track is invalid.
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| BASS_ERROR_UNKNOWN | Some other mystery problem!
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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