fix(main/python-torchvision): enable ffmpeg support and fix libjpeg a…

…nd libwebp detection

packages/python-torchvision/build.sh

@@ -3,9 +3,10 @@ TERMUX_PKG_DESCRIPTION="Datasets, Transforms and Models specific to Computer Vis
 TERMUX_PKG_LICENSE="BSD 3-Clause"
 TERMUX_PKG_MAINTAINER="@termux"
 TERMUX_PKG_VERSION=0.20.0
-TERMUX_PKG_SRCURL=git+https://github.com/pytorch/vision
-# ffmpeg
-TERMUX_PKG_DEPENDS="libc++, python, python-numpy, python-pillow, python-pip, python-torch, libjpeg-turbo, libpng, zlib"
+TERMUX_PKG_REVISION=1
+TERMUX_PKG_SRCURL=https://github.com/pytorch/vision/archive/refs/tags/v${TERMUX_PKG_VERSION}.tar.gz
+TERMUX_PKG_SHA256=b59d9896c5c957c6db0018754bbd17d079c5102b82b9be0b438553b40a7b6029
+TERMUX_PKG_DEPENDS="libc++, ffmpeg, python, python-numpy, python-pillow, python-pip, python-torch, libjpeg-turbo, libpng, libwebp, zlib"
 TERMUX_PKG_PYTHON_COMMON_DEPS="wheel, setuptools"
 
 termux_step_pre_configure() {
@@ -14,9 +15,15 @@ termux_step_pre_configure() {
 	CXXFLAGS+=" -DUSE_PYTHON"
 	LDFLAGS+=" -ltorch_cpu -ltorch_python -lc10"
 
-	# FIXME: Disable ffmpeg temporarily because torchvision doesn't support ffmpeg 6.
-	export TORCHVISION_USE_FFMPEG=0
+	# setting this $BUILD_PREFIX variable, which wasn't previously set, causes
+	# libwebp to be detected and libjpeg to be detected,
+	# and assists with detecting ffmpeg
+	export BUILD_PREFIX="$TERMUX_PREFIX"
 	export BUILD_VERSION=$TERMUX_PKG_VERSION
+
+	# this causes ffmpeg to be detected during cross-compilation,
+	# enabling the "video decoder extensions"
+	sed -i "s|shutil.which(\"ffmpeg\")|\"$TERMUX_PREFIX/bin/ffmpeg\"|" setup.py
 }
 
 termux_step_configure() {