XvSetPortAttribute(3)

💖 XvSetPortAttribute(3) — the libXv glow-up for your video port ✨

okay bestie, come sit with me, because this one is literally a libXv function and it's giving main character energy. This page is XvSetPortAttribute(3), and it lives in the libXv family. If you've ever wanted to reach into a video port and just… change its vibe? This is the girl. 🎀

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🌸 NAME 🌸

XvSetPortAttribute — sets an attribute of a video port 💅

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✨ SYNOPSIS ✨

#include <X11/extensions/Xvlib.h>

int XvSetPortAttribute(Display *dpy, XvPortID port,
                       Atom attribute, int value);

no cap, that's the whole signature. four args, one int back. iconic. 🦋

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🫶 ARGUMENTS 🫶

• dpy — the connection to the X server. your whole line to the server, basically your group chat with it.
• port — the port whose attribute is getting used. like, which port are we doing this to.
• attribute — identifies the port attribute this request is gonna set. it can be one of the table entries under the column "String," below. yep, the strings below, those ones. 👇
• value — the value that attribute is being set to. it can be one of the table entries under the column "Type," below. yes queen, cross-reference the table.

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💅 DESCRIPTION 💅

So XvSetPortAttribute(3) lets a client set the port attribute to specified values. that's it, that's the job. and this request supports the following values:

• "XV_ENCODING" — type XvEncodingID — default: Server dependent
• "XV_HUE" — type [-1000...1000] — default: 0
• "XV_SATURATION" — type [-1000...1000] — default: 0
• "XV_BRIGHTNESS" — type [-1000...1000] — default: 0
• "XV_CONTRAST" — type [-1000...1000] — default: 0

(that's the Attribute String / Type / Default situation, all five rows, nothing skipped, we keep the receipts. 🧾)

The supplied encoding must be one of the encodings listed for the adaptor, otherwise an Encoding error results. so like… don't freestyle the encoding, it will not eat. 🙈

If the adaptor does not support the exact hue, saturation, brightness, and contrast levels you supplied, the closest levels supported are assumed. it's doing its best, okay?? and heads up — use XvGetPortAttribute(3) to query the resulting levels, because what you asked for and what you got might not be twins fr fr. 🔍

When an XvSetPortAttribute(3) request is processed, a XvPortNotify(3) event is generated for all clients that have requested notification of port changes using XvSelectPortNotify(3). so everybody who signed up for the notifs gets pinged. group chat goes off. 🔔

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⭐ RETURN VALUES ⭐

• [Success] — returned if XvSetPortAttribute(3) completed successfully. slay, we ate. 💖
• [XvBadExtension] — returned if the Xv extension is unavailable. she's not here, she's not coming. 😭
• [XvBadAlloc] — returned if XvSelectVideoNotify(3) failed to allocate memory to process the request. ran out of room, tragic. 💀

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🔥 DIAGNOSTICS 🔥

• [XvBadPort] — generated if the requested port does not exist. that port is a ghost, bestie. 👻
• [XvBadEncoding] — generated if an encoding is specified that does not exist. made-up encoding? not on my watch. 🚫
• [BadMatch] — generated if the requested attribute atom does not specify an attribute supported by the adaptor. the adaptor said "never heard of her." 🙅♀️

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🌈 SEE ALSO 🌈

XvGetPortAttribute(3), XvQueryPortAttributes(3), XvSelectPortNotify(3), XvPortNotify(3)

like, go read those too, iykyk. 👑

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real talk: if the levels you asked for aren't supported, the closest ones get assumed — so always circle back with XvGetPortAttribute(3) before you trust the numbers. no guessing, just checking. 🫶

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and that's the page, periodt. 💜 this whole thing came out of X Version 11, specifically libXv 1.0.13 — so when you see XvSetPortAttribute(3) out in the wild, that's the era she's from. mwah, bye bestie! 🎀✨🦋