Input buffers (for decoders) and Output buffers (for encoders) contain encoded data according to the format’s type. For video types this data is all the encoded data representing a single moment in time, for audio data this is slightly relaxed in that a buffer may contain multiple encoded frames of audio. In either case, buffers do not start and end on arbitrary byte boundaries, this is not a stream of bytes, it’s a stream of access units.

“这不是字节流，而是访问单元流”

H.264 视频流
text
字节流视角: [00 00 00 01 67 … 00 00 00 01 68 … 00 00 00 01 65 …]
访问单元视角: [SPS] [PPS] [I帧] [P帧] [P帧] …
每个 [ ] 都是一个访问单元

必须以 00 00 00 01 或 00 00 01 开始

包含完整的编码帧信息