LEAD H264 Transcoder

The LEAD H264 is a filter. It is used to transcode h.264 video streams in NAL Unit (mpeg2) format to h.264 in ISO (mpeg4) format or vice versa. Hence, conversion can be done in either direction, from ISO format to MPEG2 format or MPEG2 format to ISO format. This filter changes h.264 packets format without performing re-compression of the video stream or the data packets. Converting with this filter is fast while the quality of the original stream is preserved. To convert an h.264 stream inside an AVI, OGG or MPEG2 transport file to ISO format or vice versa without re-compression, insert the LEAD H264 Transcoder filter between the (AVI, OGG or mpeg2) demux and the ISO multiplexer. The LEADTOOLS Multimedia toolkit automatically inserts the filter in this manner.

Filter Interface(s)	N/A
Interface ID	N/A
Input Media Types	Type: MEDIATYPE_Video Subtypes: MEDIASUBTYPE_H264 MEDIASUBTYPE_h264 ISOMEDIATYPE_avc1 MEDIASUBTYPE_avc1 MEDIASUBTYPE_AVC1
Output Media Types	Type: MEDIATYPE_Video Subtype: ISOMEDIATYPE_avc1 MEDIASUBTYPE_h264
Filter CLSID	CLSID_LMH264Transcoder
Filter category	CLSID_VideoCompressorCategory
Executable	LTranscoderH264.dll, DSKernel2.dll

Platforms

Win32, x64

To illustrate the advantage of using transcoders, two setups are provided below for comparison. Observe (Figure 1) how the transcoders are positioned between the LEAD MPEG Transport Demultiplexer and the LEAD ISO Multiplexer. Now observe the next image (Figure 2) and how, in between the same LEAD MPEG2 Transport Demultiplexer and LEAD ISO Multiplexer there is a need to use encoders and decoders. As a result of using decoding-encoding filters, the processing of data is slower than the speeds attained with data re-packetizing--a key feature of transcoders.

Figure 1. Re-packetizing of Data Using Transcoderss.