AVC1與H264的區別
http://blog.csdn.net/qiuchangyong/article/details/6660253
H.264 Video Types
The following media subtypes are defined for H.264 video.
Subtype FOURCC Description
MEDIASUBTYPE_AVC1 'AVC1' H.264 bitstream without start codes.
MEDIASUBTYPE_H264 'H264' H.264 bitstream with start codes.
MEDIASUBTYPE_h264 'h264' Equivalent to MEDIASUBTYPE_H264, with a different FOURCC.
MEDIASUBTYPE_X264 'X264' Equivalent to MEDIASUBTYPE_H264, with a different FOURCC.
MEDIASUBTYPE_x264 'x264' Equivalent to MEDIASUBTYPE_H264, with a different FOURCC.
The main difference between these media types is the presence of startcodes in the bitstream. If the subtype is MEDIASUBTYPE_AVC1, thebitstream does not contain start codes.
H264/AVC視頻解碼時AVC1和H264的區別
http://blog.csdn.net/ameyume/article/details/7542979
FOURCC:AVC1 描述:H.264 bitstream without start codes.
FOURCC:H264 描述:H.264 bitstream with start codes.
H.264 Bitstream with Start Codes
H.264 bitstreams that are transmitted over the air, or contained in MPEG-2 program or transport streams, or recorded on HD-DVD, are formatted as described in Annex B of ITU-T Rec. H.264. According to this specification, the bitstream consists of a sequence of network abstraction layer units (NALUs), each of which is prefixed with a start code equal to 0x000001 or 0x00000001.
這段話的大致意思是：帶有開始碼的H.264視頻一般是用於無線發射、有線廣播或者HD-DVD中的。這些數據流的開始都有一個開始碼：0x000001 或者 0x00000001.
H.264 Bitstream Without Start Codes
The MP4 container format stores H.264 data without start codes. Instead, each NALU is prefixed by a length field, which gives the length of the NALU in bytes. The size of the length field can vary, but is typically 1, 2, or 4 bytes.
這段話的大致意思是：沒有開始碼的H.264視頻主要是存儲在MP4格式的文件中的。它的數據流的開始是1、2或者4個字節表示長度數據。
原文中的"NALU"簡單說是H.264格式中的最基本的單元，是一個數據包。