Namespace: Un4seen.Bass.AddOn.Wma
Assembly: Bass.Net (in Bass.Net.dll) Version: 2.4.17.5
[DllImportAttribute("basswma")] public static int BASS_WMA_EncodeOpen( int freq, int chans, BASSWMAEncode flags, int bitrate, WMENCODEPROC proc, IntPtr user )
Parameters
- freq
- Type: SystemInt32
The sample rate in Hz, or a BASS channel handle if the BASS_WMA_ENCODE_SOURCE flag is specified. - chans
- Type: SystemInt32
The number of channels (1=mono, 2=stereo, etc.). - flags
- Type: Un4seen.Bass.AddOn.WmaBASSWMAEncode
Any combination of these flags (see BASSWMAEncode):BASS_SAMPLE_8BITS 8-bit sample data. If neither this or the BASS_SAMPLE_FLOAT flags are specified, then 16-bit data is expected. BASS_SAMPLE_FLOAT 32-bit floating-point sample data. BASS_WMA_ENCODE_STANDARD Use standard WMA encoding. If neither this or the BASS_WMA_ENCODE_PRO flag is specified, then either codec could be used (whichever supports the requested sample format and bitrate). BASS_WMA_ENCODE_PRO Use WMA Professional encoding. BASS_WMA_ENCODE_VOICE Use WMA voice encoding. BASS_WMA_ENCODE_VOICE_MIXED UUse WMA voice encoding in mixed mode. BASS_WMA_ENCODE_PCM Write uncompressed PCM data in an ASF container. bitrate is ignored except that it should be non-0. BASS_WMA_ENCODE_24BIT Encode in 24-bit, else 16-bit. 24-bit encoding requires WMA Pro. BASS_WMA_ENCODE_SCRIPT Enable the specification of tags mid-stream (after encoding has begun). BASS_WMA_ENCODE_SOURCE Use the BASS channel with the handle in freq as the encoder's source. The chansparameter is ignored, as are the BASS_SAMPLE_8BITS and BASS_SAMPLE_FLOAT flags. If the BASSenc add-on is loaded, then the BASS_CONFIG_ENCODE_PRIORITY setting is used to determine where in the channel's DSP chain the encoding is performed, otherwise priority -1000 is used. BASS_WMA_ENCODE_QUEUE Queue data to feed the encoder asynchronously. This prevents BASS_WMA_EncodeWrite(Int32, IntPtr, Int32) getting blocked by the encoder, but the application should control the rate at which data is encoded, as it is possible to queue too much data for the encoder to handle. - bitrate
- Type: SystemInt32
The encoding bitrate (in bits per second, e.g. 128000), or VBR quality (100 or less). - proc
- Type: Un4seen.Bass.AddOn.WmaWMENCODEPROC
The user defined function to receive the encoded data (see WMENCODEPROC). - user
- Type: SystemIntPtr
User instance data to pass to the callback function.
Return Value
Type: Int32If succesful, the new encoder's handle is returned, else 0 is returned. Use BASS_ErrorGetCode to get the error code.
Encoding to a user defined function allows any storage or delivery method to be used for the encoded WMA data. For example, encoding to memory.
The WMA codec expects 16-bit or 24-bit sample data depending on the BASS_WMA_ENCODE_24BIT flag, but BASSWMA will accept 8-bit, 16-bit or floating-point data, and convert it to the appropriate format. Use BASS_WMA_EncodeGetRates(Int32, Int32, BASSWMAEncode) to retrieve a list of the encoding bitrates available for a specific sample format.
Use BASS_WMA_EncodeSetTag(Int32, IntPtr, IntPtr, BASSWMATag) for each tag you wish to set.
Use BASS_WMA_EncodeWrite(Int32, IntPtr, Int32) to encode sample data, and BASS_WMA_EncodeClose(Int32) to finish encoding.
ERROR CODE | Description |
---|---|
BASS_ERROR_WMA | The Windows Media modules (v9 or above) are not installed. |
BASS_ERROR_NOTAVAIL | No codec could be found to support the specified sample format and bitrate. |
BASS_ERROR_UNKNOWN | Some other mystery problem! |
// the encoding callback private WMENCODEPROC _myEndoderProc; private FileStream _fs; private byte[] _encbuffer = new byte[1048510]; // 1MB buffer, should be enough ... // open a wma file _fs = File.OpenRead("test.wma"); // create the encoder (44kHz, stereo at 64kbps, no tags) _myEndoderProc = new WMENCODEPROC(MyEncodingWriter); int encoder = BassWma.BASS_WMA_EncodeOpen(44100, 2, BASSWMAEncode.BASS_WMA_ENCODE_DEFAULT, 64000, _myEndoderProc, IntPtr.Zero); ... private bool MyEncodingWriter(int handle, BASSWMAEncodeCallback type, IntPtr buffer, int length, IntPtr user) { if (type == BASSWMAEncodeCallback.BASS_WMA_ENCODE_HEAD) { // rewind to start of file to write the header _fs.Position = 0L; } if (type == BASSWMAEncodeCallback.BASS_WMA_ENCODE_DONE) { // done encoding - close the file _fs.Flush(); _fs.Close(); } else { // copy the unmanaged buffer content to out managed buffer Marshal.Copy(buffer, _encbuffer, 0, length); // process the data in _encbuffer _fs.Write(_encbuffer, 0, length); } }