From 684f75897824ccb406b4062c0e109044f6bb85f6 Mon Sep 17 00:00:00 2001
From: FreezyLemon <contact@freezylemon.com>
Date: Wed, 10 Apr 2024 15:27:50 +0200
Subject: [PATCH] Replace avutil macros with const fns & clean up some code
 (#33)

* Replace tag/error macros with const fns

* Remove c_int -> c_int cast

These should always use the same type alias

* Remove duplicate av_strerror definition

* Document breaking change
---
 CHANGELOG.md                              |  4 ++
 ffmpeg-sys-the-third/src/avutil/error.rs  | 74 +++++++++++++----------
 ffmpeg-sys-the-third/src/avutil/macros.rs | 13 ----
 ffmpeg-sys-the-third/src/avutil/mod.rs    |  3 -
 ffmpeg-sys-the-third/src/avutil/util.rs   |  3 +-
 ffmpeg-sys-the-third/src/lib.rs           |  1 -
 6 files changed, 46 insertions(+), 52 deletions(-)
 delete mode 100644 ffmpeg-sys-the-third/src/avutil/macros.rs

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f61e4bd..a027cca 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## Unreleased
+
+- Replace macros `MKTAG`, `MKBETAG` and `FFERRTAG` with const functions
+
 ## Version 1.2.2
 
 - Do a better job of fixing ffmpeg 6.0 support :)
diff --git a/ffmpeg-sys-the-third/src/avutil/error.rs b/ffmpeg-sys-the-third/src/avutil/error.rs
index cce458c..89cf0eb 100644
--- a/ffmpeg-sys-the-third/src/avutil/error.rs
+++ b/ffmpeg-sys-the-third/src/avutil/error.rs
@@ -18,39 +18,51 @@ pub const fn AVUNERROR(e: c_int) -> c_int {
     -e
 }
 
-macro_rules! FFERRTAG {
-    ($a:expr, $b:expr, $c:expr, $d:expr) => {
-        -MKTAG!($a, $b, $c, $d) as c_int
-    };
+#[inline(always)]
+pub const fn MKTAG(a: u8, b: u8, c: u8, d: u8) -> u32 {
+    u32::from_le_bytes([a, b, c, d])
 }
 
-pub const AVERROR_BSF_NOT_FOUND: c_int = FFERRTAG!(0xF8, b'B', b'S', b'F');
-pub const AVERROR_BUG: c_int = FFERRTAG!(b'B', b'U', b'G', b'!');
-pub const AVERROR_BUFFER_TOO_SMALL: c_int = FFERRTAG!(b'B', b'U', b'F', b'S');
-pub const AVERROR_DECODER_NOT_FOUND: c_int = FFERRTAG!(0xF8, b'D', b'E', b'C');
-pub const AVERROR_DEMUXER_NOT_FOUND: c_int = FFERRTAG!(0xF8, b'D', b'E', b'M');
-pub const AVERROR_ENCODER_NOT_FOUND: c_int = FFERRTAG!(0xF8, b'E', b'N', b'C');
-pub const AVERROR_EOF: c_int = FFERRTAG!(b'E', b'O', b'F', b' ');
-pub const AVERROR_EXIT: c_int = FFERRTAG!(b'E', b'X', b'I', b'T');
-pub const AVERROR_EXTERNAL: c_int = FFERRTAG!(b'E', b'X', b'T', b' ');
-pub const AVERROR_FILTER_NOT_FOUND: c_int = FFERRTAG!(0xF8, b'F', b'I', b'L');
-pub const AVERROR_INVALIDDATA: c_int = FFERRTAG!(b'I', b'N', b'D', b'A');
-pub const AVERROR_MUXER_NOT_FOUND: c_int = FFERRTAG!(0xF8, b'M', b'U', b'X');
-pub const AVERROR_OPTION_NOT_FOUND: c_int = FFERRTAG!(0xF8, b'O', b'P', b'T');
-pub const AVERROR_PATCHWELCOME: c_int = FFERRTAG!(b'P', b'A', b'W', b'E');
-pub const AVERROR_PROTOCOL_NOT_FOUND: c_int = FFERRTAG!(0xF8, b'P', b'R', b'O');
+#[inline(always)]
+pub const fn MKBETAG(a: u8, b: u8, c: u8, d: u8) -> u32 {
+    u32::from_be_bytes([a, b, c, d])
+}
 
-pub const AVERROR_STREAM_NOT_FOUND: c_int = FFERRTAG!(0xF8, b'S', b'T', b'R');
+#[inline(always)]
+pub const fn FFERRTAG(a: u8, b: u8, c: u8, d: u8) -> c_int {
+    let tag = MKTAG(a, b, c, d);
+    assert!(c_int::MAX as u32 >= tag, "error tag must fit inside c_int");
 
-pub const AVERROR_BUG2: c_int = FFERRTAG!(b'B', b'U', b'G', b' ');
-pub const AVERROR_UNKNOWN: c_int = FFERRTAG!(b'U', b'N', b'K', b'N');
+    -(tag as c_int)
+}
 
-pub const AVERROR_HTTP_BAD_REQUEST: c_int = FFERRTAG!(0xF8, b'4', b'0', b'0');
-pub const AVERROR_HTTP_UNAUTHORIZED: c_int = FFERRTAG!(0xF8, b'4', b'0', b'1');
-pub const AVERROR_HTTP_FORBIDDEN: c_int = FFERRTAG!(0xF8, b'4', b'0', b'3');
-pub const AVERROR_HTTP_NOT_FOUND: c_int = FFERRTAG!(0xF8, b'4', b'0', b'4');
-pub const AVERROR_HTTP_OTHER_4XX: c_int = FFERRTAG!(0xF8, b'4', b'X', b'X');
-pub const AVERROR_HTTP_SERVER_ERROR: c_int = FFERRTAG!(0xF8, b'5', b'X', b'X');
+pub const AVERROR_BSF_NOT_FOUND: c_int = FFERRTAG(0xF8, b'B', b'S', b'F');
+pub const AVERROR_BUG: c_int = FFERRTAG(b'B', b'U', b'G', b'!');
+pub const AVERROR_BUFFER_TOO_SMALL: c_int = FFERRTAG(b'B', b'U', b'F', b'S');
+pub const AVERROR_DECODER_NOT_FOUND: c_int = FFERRTAG(0xF8, b'D', b'E', b'C');
+pub const AVERROR_DEMUXER_NOT_FOUND: c_int = FFERRTAG(0xF8, b'D', b'E', b'M');
+pub const AVERROR_ENCODER_NOT_FOUND: c_int = FFERRTAG(0xF8, b'E', b'N', b'C');
+pub const AVERROR_EOF: c_int = FFERRTAG(b'E', b'O', b'F', b' ');
+pub const AVERROR_EXIT: c_int = FFERRTAG(b'E', b'X', b'I', b'T');
+pub const AVERROR_EXTERNAL: c_int = FFERRTAG(b'E', b'X', b'T', b' ');
+pub const AVERROR_FILTER_NOT_FOUND: c_int = FFERRTAG(0xF8, b'F', b'I', b'L');
+pub const AVERROR_INVALIDDATA: c_int = FFERRTAG(b'I', b'N', b'D', b'A');
+pub const AVERROR_MUXER_NOT_FOUND: c_int = FFERRTAG(0xF8, b'M', b'U', b'X');
+pub const AVERROR_OPTION_NOT_FOUND: c_int = FFERRTAG(0xF8, b'O', b'P', b'T');
+pub const AVERROR_PATCHWELCOME: c_int = FFERRTAG(b'P', b'A', b'W', b'E');
+pub const AVERROR_PROTOCOL_NOT_FOUND: c_int = FFERRTAG(0xF8, b'P', b'R', b'O');
+
+pub const AVERROR_STREAM_NOT_FOUND: c_int = FFERRTAG(0xF8, b'S', b'T', b'R');
+
+pub const AVERROR_BUG2: c_int = FFERRTAG(b'B', b'U', b'G', b' ');
+pub const AVERROR_UNKNOWN: c_int = FFERRTAG(b'U', b'N', b'K', b'N');
+
+pub const AVERROR_HTTP_BAD_REQUEST: c_int = FFERRTAG(0xF8, b'4', b'0', b'0');
+pub const AVERROR_HTTP_UNAUTHORIZED: c_int = FFERRTAG(0xF8, b'4', b'0', b'1');
+pub const AVERROR_HTTP_FORBIDDEN: c_int = FFERRTAG(0xF8, b'4', b'0', b'3');
+pub const AVERROR_HTTP_NOT_FOUND: c_int = FFERRTAG(0xF8, b'4', b'0', b'4');
+pub const AVERROR_HTTP_OTHER_4XX: c_int = FFERRTAG(0xF8, b'4', b'X', b'X');
+pub const AVERROR_HTTP_SERVER_ERROR: c_int = FFERRTAG(0xF8, b'5', b'X', b'X');
 
 #[inline(always)]
 pub unsafe fn av_make_error_string(
@@ -58,11 +70,7 @@ pub unsafe fn av_make_error_string(
     errbuf_size: size_t,
     errnum: c_int,
 ) -> *mut c_char {
-    av_strerror(errnum, errbuf, errbuf_size);
+    crate::av_strerror(errnum, errbuf, errbuf_size);
 
     errbuf
 }
-
-extern "C" {
-    pub fn av_strerror(errnum: c_int, errbuf: *mut c_char, errbuf_size: size_t) -> c_int;
-}
diff --git a/ffmpeg-sys-the-third/src/avutil/macros.rs b/ffmpeg-sys-the-third/src/avutil/macros.rs
deleted file mode 100644
index a50636e..0000000
--- a/ffmpeg-sys-the-third/src/avutil/macros.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-#[macro_export]
-macro_rules! MKBETAG {
-    ($a:expr, $b:expr, $c:expr, $d:expr) => {
-        ($d as isize) | (($c as isize) << 8) | (($b as isize) << 16) | (($a as isize) << 24)
-    };
-}
-
-#[macro_export]
-macro_rules! MKTAG {
-    ($a:expr, $b:expr, $c:expr, $d:expr) => {
-        ($a as isize) | (($b as isize) << 8) | (($c as isize) << 16) | (($d as isize) << 24)
-    };
-}
diff --git a/ffmpeg-sys-the-third/src/avutil/mod.rs b/ffmpeg-sys-the-third/src/avutil/mod.rs
index c48bcfb..7a93e14 100644
--- a/ffmpeg-sys-the-third/src/avutil/mod.rs
+++ b/ffmpeg-sys-the-third/src/avutil/mod.rs
@@ -1,6 +1,3 @@
-#[macro_use]
-mod macros;
-
 mod error;
 pub use self::error::*;
 
diff --git a/ffmpeg-sys-the-third/src/avutil/util.rs b/ffmpeg-sys-the-third/src/avutil/util.rs
index 22a310c..8890d0d 100644
--- a/ffmpeg-sys-the-third/src/avutil/util.rs
+++ b/ffmpeg-sys-the-third/src/avutil/util.rs
@@ -1,8 +1,7 @@
-use libc::c_int;
 use crate::{AVRational, AV_TIME_BASE};
 
 pub const AV_NOPTS_VALUE: i64 = 0x8000000000000000u64 as i64;
 pub const AV_TIME_BASE_Q: AVRational = AVRational {
     num: 1,
-    den: AV_TIME_BASE as c_int,
+    den: AV_TIME_BASE,
 };
diff --git a/ffmpeg-sys-the-third/src/lib.rs b/ffmpeg-sys-the-third/src/lib.rs
index 331055f..b661126 100644
--- a/ffmpeg-sys-the-third/src/lib.rs
+++ b/ffmpeg-sys-the-third/src/lib.rs
@@ -11,6 +11,5 @@ extern crate libc;
 
 include!(concat!(env!("OUT_DIR"), "/bindings.rs"));
 
-#[macro_use]
 mod avutil;
 pub use crate::avutil::*;