1、問題描述

在使用GStreamer生成h.264的rtmp流時，不知道怎么設置h.264的profile級別。默認一直是“high”：

video/x-h264, ... profile=(string)high, ...

2、解決方法

查看官網手冊中，有如下解釋
The H264 profile that is eventually used depends on a few settings. If “dct8x8” is enabled, then High profile is used. Otherwise, if “cabac” entropy coding is enabled or “bframes” are allowed, then Main Profile is in effect, and otherwise Baseline profile applies. The high profile is imposed by default, which is fine for most software players and settings, but in some cases (e.g. hardware platforms) a more restricted profile/level may be necessary. The recommended way to set a profile is to set it in the downstream caps.
意思是h264的profile級別是由一些設置決定的。默認是high配置。
將 dct8x8 設置為false，可以將profile級別由 high 降為 main。使用如下方法：