https://github.com/kfish/libshcodecs

A library for controlling SH-Mobile hardware codecs
https://github.com/kfish/libshcodecs

Last synced: 26 days ago
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A library for controlling SH-Mobile hardware codecs

• Host: GitHub
• URL: https://github.com/kfish/libshcodecs
• Owner: kfish
• License: other
• Created: 2009-03-27T06:27:07.000Z (almost 16 years ago)
• Default Branch: master
• Last Pushed: 2010-08-09T22:21:26.000Z (over 14 years ago)
• Last Synced: 2024-10-15T15:12:25.817Z (2 months ago)
• Language: C
• Homepage:
• Size: 916 KB
• Stars: 5
• Watchers: 6
• Forks: 3
• Open Issues: 0
• Metadata Files:
  • Readme: README
  • Changelog: ChangeLog
  • License: COPYING

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README

        
libshcodecs

===========

libshcodecs: A library for controlling SH-Mobile hardware codecs

Copyright (C) 2009 Renesas Technology Corp.

The [SH-Mobile][0] processor series includes a hardware video processing

unit that supports MPEG-4 and H.264 encoding and decoding.

This source archive contains:

 * src/libshcodecs: the libshcodecs shared library

 * src/examples: various examples of simple uses of libshcodecs

 * src/tools: commandline tools

tools

-----

The following tools are provided:

 * shcodecs-dec: Decode a video file to YUV data

 * shcodecs-enc: Encode a video file from YUV data

 * shcodecs-play: Play a file on the framebuffer

 * shcodecs-record: Record video from a V4L2 camera device

For usage details see the corresponding man pages or run with the option

--help.

libshcodecs

-----------

libshcodecs provides callback-based interfaces for encoding and decoding

video streams.

To decode video data, an application provides a callback with the following

prototype:

    int vpu4_decoded (SHCodecs_Decoder * decoder,

                      unsigned char * y_buf, int y_size,

                      unsigned char * c_buf, int c_size,

                      void * user_data);

and then supplies encoded video data to the function:

    shcodecs_decode (decoder, input_buffer, length);

The decoder will process the input buffer, and call the provided callback

function each time a frame is decoded. The output is given in two bitplanes

of YUV 4:2:0.

For a full decoder example, see src/tools/shcodecs-dec.c

To encode video data, an application provides both input and output callback

functions:

    /* SHCodecs_Encoder_Input callback for acquiring an image */

    int get_input(SHCodecs_Encoder * encoder, void *user_data);

    

    /* SHCodecs_Encoder_Output callback for writing encoded data */

    int write_output(SHCodecs_Encoder * encoder,

                     unsigned char *data, int length, void *user_data);

and then run the encoder by:

    shcodecs_encoder_run(encoder);

The encoder will retrieve raw video as needed using the input callback, and will

use the output callback you have provided whenever encoded video data is

available.

For examples of encoding from file and camera, see src/tools/shcodecs-enc.c

and src/tools/shcodecs-record.c.

SH-Mobile

---------

The [SH-Mobile][0] processor series includes a hardware video processing

unit that supports MPEG-4 and H.264 encoding and decoding. Some models

also include support for camera capture, JPEG processing, and DSP

instructions.

[0]: http://www.renesas.com/fmwk.jsp?cnt=sh_mobile_family_landing.jsp&fp=/products/mpumcu/sh_mobile/

Kernel configuration

--------------------

libshcodecs uses the Linux kernel UIO support for the SH-Mobile VPU, which was

added in 2.6.27.

The following kernel boot option reserves physically contiguous memory for VPU use:

    memchunk.vpu=4m

In order to encode 2 video streams, this amount reserved should be increased:

    memchunk.vpu=8m

License

-------

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Library General Public

License as published by the Free Software Foundation; either

version 2 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

Library General Public License for more details.

You should have received a copy of the GNU Library General Public

License along with this library; if not, write to the Free Software

Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA  02110-1301 USA

See the file COPYING for details.