H.264和HEVC如何正確的丟幀

播放器內部邏輯肯定是存在丟幀的邏輯的，只有丟掉不被依賴的幀纔不會導致花屏，RFC中有說明。

H.264

具體可以參考rfc3984#section-1.3，也就是nal_ref_idc的值爲0時，此幀可以被丟棄。

NRI: 2 bits
      nal_ref_idc.  A value of 00 indicates that the content of the NAL
      unit is not used to reconstruct reference pictures for inter
      picture prediction.  Such NAL units can be discarded without
      risking the integrity of the reference pictures.  Values greater
      than 00 indicate that the decoding of the NAL unit is required to
      maintain the integrity of the reference pictures.

HEVC

具體可以參考rfc7798#section-1.1.2，也就是nal_unit_type類型爲RASL_N和RASL_R時，此幀可以被丟棄。

There are two
   types of leading pictures: Random Access Decodable Leading (RADL)
   pictures and Random Access Skipped Leading (RASL) pictures.  RADL
   pictures are decodable when the decoding started at the associated
   IRAP picture; RASL pictures are not decodable when the decoding
   started at the associated IRAP picture and are usually discarded.
   HEVC provides mechanisms to enable specifying the conformance of a
   bitstream wherein the originally present RASL pictures have been
   discarded.  Consequently, system components can discard RASL
   pictures, when needed, without worrying about causing the bitstream
   to become non-compliant.