In fact, the probability of this situation is very small 1:2^22. At this time, it needs to be treated with emulation prevention, also called escape, that isĪdd 03 when encoding and go to 03 when decoding. If the RBSP contains bytes similar to the start code, it will be troublesome.
NALU is a nalu type plus EBSP, why is it EBSP instead of RBSP? Because the raw h264 format code stream is also called h264 ES stream, the start code is used to split each NALU. The NAL layer is above the VCL layer, and the decoder must go from the NAL layer to the VCL layer when decoding, while the encoding process is the opposite.īasically the process NALU -> RBSP -> SODB Among them, the NALU whose nalu type is 1-5 is called VCL NALU, and the others are called non-VCL NALU. NAL is composed of a series of NALU units. The code stream of h264 is divided into VCL layer and NAL layer.
In fact, it is in the ffmpeg/libavcodec/h264_mp4toannexb_bsf.c file. The second command line converts the mp4 file containing h264 encoding to the ts file formatīoth use bitstream filter: h264_mp4toannexb, which is used to convert the byte length prefix to the start code prefix. The first command line extracts the h264 video stream in the mp4 file containing h264 encoding and saves it as raw h264 format The following two command lines realize file format conversion:įfmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264įfmpeg -i INPUT.mp4 -codec copy -bsf:v h264_mp4toannexb OUTPUT.ts
0 kommentar(er)
