av1_vaapi use -q & --max-crf 255

CHANGELOG.md

@@ -1,5 +1,7 @@
 # Unreleased
 * Show full ffmpeg command after errors.
+* For *_vaapi encoders map `--crf` to ffmpeg `-q` (instead of `-qp`).
+* Set av1_vaapi default `--max-crf` to 255.
 
 # v0.7.14
 * Fix bash completions of some filenames.

src/command/args/encode.rs

@@ -338,8 +338,8 @@ impl Encoder {
     pub fn default_max_crf(&self) -> f32 {
         match self.as_str() {
             "libx264" | "libx265" => 46.0,
-            // rav1e: use max -qp
             "librav1e" => 255.0,
+            "av1_vaapi" => 255.0,
             // Works well for svt-av1
             _ => 55.0,
         }

src/ffmpeg.rs

@@ -202,15 +202,16 @@ impl VCodecSpecific for Arc<str> {
     }
 
     fn crf_arg(&self) -> &str {
-        // use crf-like args to support encoders that don't have crf
-        if &**self == "librav1e" || self.ends_with("_vaapi") {
-            "-qp"
-        } else if self.ends_with("_nvenc") {
-            "-cq"
-        } else if self.ends_with("_qsv") {
-            "-global_quality"
-        } else {
-            "-crf"
+        // // use crf-like args to support encoders that don't have crf
+        match &**self {
+            // https://ffmpeg.org//ffmpeg-codecs.html#librav1e
+            "librav1e" => "-qp",
+            // https://ffmpeg.org//ffmpeg-codecs.html#VAAPI-encoders
+            e if e.ends_with("_vaapi") => "-q",
+            e if e.ends_with("_nvenc") => "-cq",
+            // https://ffmpeg.org//ffmpeg-codecs.html#QSV-Encoders
+            e if e.ends_with("_qsv") => "-global_quality",
+            _ => "-crf",
         }
     }
 }