[BUG] Demuxer behavior if FFmpeg is not found #185
Description
Describe the bug
If libswscale is not found, the build reports FFmpeg not found.
libswscale is optional, if it is not available, FFmpeg should still be found.
Additionally, when FFmpeg is not found, decoding fails for both: debug and release builds in different ways.
See Observed Behavior for details.
Setup
- OS: Ubuntu 24.04.4 LTS
- GPU: NVIDIA GeForce RTX 4060 Ti
- Driver Version: Mesa 26.1.0-devel (git-055aec542e)
- Sample Application: decoder
- Sample Application Version: v0.4.2
Expected Behavior
The libswscale library is optional, if it is not found in the system, FFmpeg should still be found.
If FFmpeg is not found, and no codec is specified, release and debug builds should fail with a proper error.
Observed Behavior
The first noticeable problem is the warning when cmake is executed.
-- Could NOT find FFmpeg (missing: SWSCALE_LIBRARY)
CMake Warning at CMakeLists.txt:132 (message):
Can't find libavcodec, libavformat, or libavutil on Linux!
CMake Warning at CMakeLists.txt:137 (message):
FFMPEG demuxing is not going to be supported.
If the decoder is used, the behavior is different for release and debug builds.
Debug build
vk-video-dec-test: $VVS_DIR/vk_video_decoder/libs/VkDecoderUtils/VideoStreamDemuxer.cpp:42: static VkResult
VideoStreamDemuxer::Create(const char*, VkVideoCodecOperationFlagBitsKHR, bool, int32_t, int32_t, int32_t,
VkSharedBaseObj<VideoStreamDemuxer>&): Assertion `codecType != VK_VIDEO_CODEC_OPERATION_NONE_KHR' failed.
Aborted (core dumped)
Release build
ERROR: Found physical device with name: NVIDIA GeForce RTX 4060 Ti, vendor ID: 10de, and device ID: 2803 NOT having the required
queue families!
Video decode queue family not supported by hardware/driver
Steps to Reproduce
- System with FFmpeg support but libswscale not installed.
- Run the decoder tests using the test framework.