ffmpeg: make nvidia dependencies explicit

pkgs/development/libraries/ffmpeg/generic.nix

@@ -47,12 +47,14 @@
 , withCelt ? withFullDeps # CELT decoder
 , withChromaprint ? withFullDeps # Audio fingerprinting
 , withCoreImage ? withHeadlessDeps && stdenv.isDarwin # Apple CoreImage framework
-, withCuda ? withFullDeps && (with stdenv; (!isDarwin && !hostPlatform.isAarch && !hostPlatform.isRiscV))
+, withCuda ? withFullDeps && withNvcodec
 , withCudaLLVM ? withFullDeps
+, withCuvid ? withHeadlessDeps && withNvcodec
 , withDav1d ? withHeadlessDeps # AV1 decoder (focused on speed and correctness)
 , withDc1394 ? withFullDeps && !stdenv.isDarwin # IIDC-1394 grabbing (ieee 1394)
 , withDrm ? withHeadlessDeps && (with stdenv; isLinux || isFreeBSD) # libdrm support
 , withFdkAac ? withFullDeps && (!withGPL || withUnfree) # Fraunhofer FDK AAC de/encoder
+, withNvcodec ? withHeadlessDeps && (with stdenv; !isDarwin && !isAarch32 && !hostPlatform.isRiscV && hostPlatform == buildPlatform) # dynamically linked Nvidia code
 , withFlite ? withFullDeps # Voice Synthesis
 , withFontconfig ? withHeadlessDeps # Needed for drawtext filter
 , withFreetype ? withHeadlessDeps # Needed for drawtext filter
@@ -70,8 +72,8 @@
 , withModplug ? withFullDeps && !stdenv.isDarwin # ModPlug support
 , withMp3lame ? withHeadlessDeps # LAME MP3 encoder
 , withMysofa ? withFullDeps # HRTF support via SOFAlizer
-, withNvdec ? withHeadlessDeps && (with stdenv; !isDarwin && hostPlatform == buildPlatform && !isAarch32 && !hostPlatform.isRiscV)
+, withNvdec ? withHeadlessDeps && withNvcodec
-, withNvenc ? withHeadlessDeps && (with stdenv; !isDarwin && hostPlatform == buildPlatform && !isAarch32 && !hostPlatform.isRiscV)
+, withNvenc ? withHeadlessDeps && withNvcodec
 , withOgg ? withHeadlessDeps # Ogg container used by vorbis & theora
 , withOpenal ? withFullDeps # OpenAL 1.1 capture support
 , withOpencl ? withFullDeps
@@ -356,6 +358,11 @@ assert buildAvformat -> buildAvcodec && buildAvutil; # configure flag since 0.6
 assert buildPostproc -> buildAvutil;
 assert buildSwscale -> buildAvutil;
 
+/*
+ *  External Library dependencies
+ */
+assert (withCuda || withCuvid || withNvdec  || withNvenc) -> withNvcodec;
+
 stdenv.mkDerivation (finalAttrs: {
   pname = "ffmpeg" + (optionalString (ffmpegVariant != "small") "-${ffmpegVariant}");
   inherit version;
@@ -509,10 +516,12 @@ stdenv.mkDerivation (finalAttrs: {
     (enableFeature withCoreImage "coreimage")
     (enableFeature withCuda "cuda")
     (enableFeature withCudaLLVM "cuda-llvm")
+    (enableFeature withCuvid "cuvid")
     (enableFeature withDav1d "libdav1d")
     (enableFeature withDc1394 "libdc1394")
     (enableFeature withDrm "libdrm")
     (enableFeature withFdkAac "libfdk-aac")
+    (enableFeature withNvcodec "ffnvcodec")
     (enableFeature withFlite "libflite")
     (enableFeature withFontconfig "fontconfig")
     (enableFeature withFontconfig "libfontconfig")
@@ -533,7 +542,6 @@ stdenv.mkDerivation (finalAttrs: {
     (enableFeature withModplug "libmodplug")
     (enableFeature withMp3lame "libmp3lame")
     (enableFeature withMysofa "libmysofa")
-    (enableFeature withNvdec "cuvid")
     (enableFeature withNvdec "nvdec")
     (enableFeature withNvenc "nvenc")
     (enableFeature withOpenal "openal")
@@ -642,6 +650,7 @@ stdenv.mkDerivation (finalAttrs: {
   ++ optionals withDc1394 [ libdc1394 libraw1394 ]
   ++ optionals withDrm [ libdrm ]
   ++ optionals withFdkAac [ fdk_aac ]
+  ++ optionals withNvcodec [ (if (lib.versionAtLeast version "6") then nv-codec-headers-12 else nv-codec-headers) ]
   ++ optionals withFlite [ flite ]
   ++ optionals withFontconfig [ fontconfig ]
   ++ optionals withFreetype [ freetype ]
@@ -659,7 +668,6 @@ stdenv.mkDerivation (finalAttrs: {
   ++ optionals withModplug [ libmodplug ]
   ++ optionals withMp3lame [ lame ]
   ++ optionals withMysofa [ libmysofa ]
-  ++ optionals (withNvdec || withNvenc) [ (if (lib.versionAtLeast version "6") then nv-codec-headers-12 else nv-codec-headers) ]
   ++ optionals withOgg [ libogg ]
   ++ optionals withOpenal [ openal ]
   ++ optionals withOpencl [ ocl-icd opencl-headers ]