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| Tech
Tips
- MPEG
to H.264 Transcoding |
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Overview
MPEGRepairHD’s transcoding ability can
be used to convert your old MPEG content into the new highly compressed
AVC/H.264 encoding standard in a single easy pass operation.
Demo
A demonstration of the MPEG to H.264 transcoding
capability of MPEGRepairHD can be obtained at h264transcodedemo.zip. Just
unzip the directory structure and launch the Mpg2H264.bat program.
The demo program will automatically transcode the
included MPEG file called flowers.mpg into anAVC/H.264 file called
flowers.264.
Transcoding using the MPEGRepairHD GUI
MPEGRepair transcoding is accomplished by browsing
to or entering the source MPEG file you wish to transcode in the
Encode Input edit box. The source MPEG can be an elementary,
program, transport, VOB, or system stream. MPEGRepairHD will
automatically determine the input file format and extract and decode
the individual frames during the transcoding process*.
Once you have set up the MPEG source for the
transcode, you can next configure the actual re-encoding process
using the Optimize Encode | Configure and Preprocess settings as
needed. The
H.264 encoding is controlled entirely in the Configure | H.264 dialog
box. Check
the Encode Using H.264 box at the top of the dialog. Be certain
to update the Frame Width and Frame Height in this dialog as well. The
Source Pictures can be used to specify the number of frames to transcode
if you wish to transcode fewer frames than exist in the source video. Remember
that settings in other dialogs do not affect the H.264 encoding.
You can use the PreProcessing options to re-size
the source video before encoding. The H.264 Frame Width and
Frame Height should be identical to the frame size resulting from
the PreProcess option if used.
Click
on image to see larger view
Depress the Encode Run button to start the transcoding process.
Transcoding using the WorkShop SDK
The Expert WorkShop SDK can be used to decode
each frame into memory. Be sure to provide each DecodeNextFrame function
call with pointer to a memory buffer that will hold the entire frame. We
recommend that you specify a frame type of YUV as that is the native
MPEG storage format.
The Expert H.264 WorkShop SDK can be used to encode each frame as
it is decoded using the above decoding process.
Specifications
Transcoding source can be any multiplexed or
elementary MPEG 1 or MPEG 2 source file including transport, program,
VOB, and system streams. The
H.264 encoding can be to baseline, main or extended profile at levels
1.0 through 5.1. Encoding can be from all I frame through
only one I frame per video. Encoding can use from 1 through 5
reference frames. Frame sizes can be from 16x16 through 16384 x 16384.
Encoding can be constant quantization (variable bit-rate) or constant
bit-rate
*The original SD 3.0 mbps mpeg file will be transocded
into a 0.7 mbps H.264 file.
MPEGRepairHD
and ExpertWorkshop SDK are trademarks of PixelTools Corporation.
All other brand names are trademarks or registered trademarks of
their respected holders
©1998-2007
PixelTools Corporation |