@param s parser context.
@param avctx codec context.
@param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
@param poutbuf_size set to size of parsed buffer or zero if not yet finished.
@param buf input buffer.
@param buf_size input length, to signal EOF, this should be 0 (so that the last frame can be output).
@param pts input presentation timestamp.
@param dts input decoding timestamp.
@param pos input byte position in stream.
@return the number of bytes of the input bitstream used.
Parse a packet.
@param s parser context. @param avctx codec context. @param poutbuf set to pointer to parsed buffer or NULL if not yet finished. @param poutbuf_size set to size of parsed buffer or zero if not yet finished. @param buf input buffer. @param buf_size input length, to signal EOF, this should be 0 (so that the last frame can be output). @param pts input presentation timestamp. @param dts input decoding timestamp. @param pos input byte position in stream. @return the number of bytes of the input bitstream used.