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h264-resource-wip:avchd

This is an old revision of the document!


This is a work in progress of AVCHD resource and info. Things we know need to be rewritten and simplified and put in here.

What is AVCHD?

Definition; AVCHD (Advanced Video Coding High Definition) is part of the AVC standard. AVCHD was jointly developed by Panasonic and Sony and introduced in 2006 primarily for use in high definition consumer camcorders. AVCHD is the codec of choice for the Panasonic GH1 and GH2. For a full description and reference please visit: http://en.wikipedia.org/wiki/AVCHD

Specification

Click this link for a full specification to AVCHD: http://www.avchd-info.org/format/index.html

AVCHD Conformance

How does the GH2 AVCHD codec conform to the standard & profiles?

AVCHD Prediction

Definition; A macroblock is a series of non-overlapping 4 by 4 (4×4) or 8 by 8 (8×8) pixel blocks which put together make up the composition of the coded picture frame. In AVCHD GH2 terms, these mbs (macroblocks) are divided into 4×4 blocks. Every macroblock has a prediction - an attempt to recreate the information inside the macroblock using previously coded data which is then subtracted from the macroblock to form the quantity left over - known as the residual. How much residual data is left over dictates how well the compression is working. Less residual = better compression performance. AVCHD has many of the effecient prediction methods described in the H.264/AVC standard.

  • Macroblock prediction - Macroblock (mb) prediction works as follows; an I-mb predicts from neighbouring samples in the frame, a P-mb inside the current frame is predicted from a previous or future coded frame, whereras a B-mb is predicted from a combination of a forward and/or backward coded frames.
  • Intra prediction - Intra predicition works in…

4×4 luma prediction

  16x16 luma prediction
  chroma prediction
  8x8 luma prediction
  Intra prediction modes of GH2
Inter prediction
  IRD Reference pictures
  Insertion of reference pictures
  Macroblock partitions
  Motion vector prediction
  Motion compensation
  Inter prediction examples (GH2)
  
Loop Filter
  Definition

Deblocking

  Examples & Summary

AVCHD Transform & Quantization

Definition, 
Transform & Quantization
  Process
  Transform & quantization of 4x4 blocks
  *Transform & quantization of 8x8 blocks is not used in GH2 
  Quajntization Scaling Tables
  DC transforms
Coding (CAVLC/CABAC)

AVCHD/GH2 Rate Control

Definition1,
Choosing the right bitrate & IQ and Q (Quantisation)
GOP (Group of Pictures)
GH2's Time Limits
GH2's Video & Video 24 Buffers
*     0x01800000 = 25165824 Dec
*     0x02400000 = 37748736 Dec
*     0x02800000 = 41943040 Dec
*     0x03000000 = 50331648 Dec
*     0x03600000 = 56623104 Dec
GH2's Frame Limits
GH2's Frame buffer size

AVCHD Stream Analysis

//Definition2,//
Using Streamparser
Other tools
  Elecard Streameye Studio Lite & Pro
  

Handling AVCHD Files

//Definition3,//
AVCHD File Structure .mts
Playback InCamera
Import into computer 
Editing & conversion
.mts Repair tools

Other#4

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Other#5

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Other#6

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h264-resource-wip/avchd.1329271130.txt.gz · Last modified: 2012/02/15 01:58 by driftwood