Description of problem:
Per https://discuss.kde.org/t/in-kdenlive-why-is-the-amount-of-time-to-encode-vp8-webm-850-more-than-h264-mpeg-4/33734/7?u=rokejulianlockhart, I created a custom profile profile based upon the WEBM one, but with solely the codec replaced by vp8_vaapi. Running the KCrash under GDB, I see, with `bt full` after invoking its recommendation of `dnf --enablerepo='*debug*' install ffmpeg-libs-debuginfo-7.1.1-5.fc42.x86_64 libavdevice-debuginfo-7.1.1-5.fc42.x86_64 x264-libs-debuginfo-0.164-16.20231001git31e19f92.fc42.x86_64 x265-libs-debuginfo-4.1-2.fc42.x86_64 openh264-debuginfo-2.4.1-2.fc42.x86_64 mesa-va-drivers-freeworld-debuginfo-25.0.4-1.fc42.x86_64`:

> ~~~log
> Core was generated by `/usr/bin/melt-7 -loglevel error -progress2 /tmp/kdenlive-xWVosr-1.mlt'.
> Program terminated with signal SIGSEGV, Segmentation fault.
> #0  0x00007fb188cf01fd in consumer_thread (arg=<optimized out>) at /usr/src/debug/mlt-7.30.0-1.fc42.x86_64/src/modules/avformat/consumer_avformat.c:2425
> 2425                            if (c->codec->id == AV_CODEC_ID_RAWVIDEO) {
> [Current thread is 1 (Thread 0x7fb1495fb6c0 (LWP 396057))]
> Function(s) ^std::(move|forward|as_const|(__)?addressof) will be skipped when stepping.
> Function(s) ^std::(shared|unique)_ptr<.*>::(get|operator) will be skipped when stepping.
> Function(s) ^std::(basic_string|vector|array|deque|(forward_)?list|(unordered_|flat_)?(multi)?(map|set)|span)<.*>::(c?r?(begin|end)|front|back|data|size|empty) will be skipped when stepping.
> Function(s) ^std::(basic_string|vector|array|deque|span)<.*>::operator.] will be skipped when stepping.
> (gdb) bt full
> #0  0x00007fb188cf01fd in consumer_thread (arg=<optimized out>) at /usr/src/debug/mlt-7.30.0-1.fc42.x86_64/src/modules/avformat/consumer_avformat.c:2425
>         pkt = {buf = 0x0, pts = -9223372036854775808, dts = -9223372036854775808, data = 0x0, size = 0, stream_index = 0, flags = 0, side_data = 0x0, side_data_elems = 0, duration = 0, pos = -1, opaque = 0x0, opaque_ref = 0x0, time_base = {
>             num = 0, den = 1}}
>         ret = <optimized out>
>         c = 0x7fb1240019c0
>         i = <optimized out>
>         enc_ctx = <optimized out>
>         consumer = <optimized out>
>         properties = <optimized out>
>         real_time_output = -1
>         ante = {tv_sec = 1746447038, tv_usec = 854722}
>         fps = 60
>         width = 2560
>         height = 1440
>         img_width = 2560
>         img_height = 1440
>         pcm = 0x7fb0f803f480
>         samples = 800
>         video_outbuf_size = 67108864
>         video_outbuf = 0x7fb107fff040 ""
>         frame = 0x7fb0f8000ba0
>         frame_properties = 0x7fb0f8000ba0
>         queue = 0x55d353603cd0
>         image = 0x7fb0edffc020 "Հ׀ـ݀\340\200\342\200\342\200\342\200\341\200߀ހހ߀\340\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200\341\200", <incomplete sequence \341\200>...
>         img_fmt = mlt_image_yuv422
>         converted_avframe = <optimized out>
>         avframe = 0x7fb12431e580
>         count = <optimized out>
>         frames = <optimized out>
>         total_time = <optimized out>
>         fmt = <optimized out>
>         filename = 0x55d353607a00 "/home/RokeJulianLockhart/Videos/@{'Name'='Android Studio'}#.webm"
>         format = <optimized out>
>         vcodec = <optimized out>
>         acodec = <optimized out>
>         audio_codec = <optimized out>
>         video_codec = <optimized out>
>         key = "channels.7", '\000' <repeats 16 times>
>         header_written = <optimized out>
>         dst_colorspace = 709
>         color_range = <optimized out>
>         dst_full_range = 0
>         aud_fmt = mlt_audio_f32le
>         pix_fmt = AV_PIX_FMT_NV12
> #1  0x00007fb18f3c31d4 in start_thread (arg=<optimized out>) at pthread_create.c:448
>         ret = <optimized out>
>         pd = <optimized out>
>         out = <optimized out>
>         unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140399416948416, 7024583510614338830, 140399416948416, 140722817675376, 22, 140722817675639, 7024583510639504654, 7025010391689325838}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, 
>             data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
>         not_first_call = <optimized out>
> #2  0x00007fb18f445cec in __GI___clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:78
> No locals.
> ~~~

Version-Release number of selected component:
mlt-7.30.0-1.fc42

Additional info:
reporter:       libreport-2.17.15
type:           CCpp
reason:         melt-7 killed by SIGSEGV
journald_cursor: s=c1f108f1ef4e48808a377c0a73f168fc;i=3f2403;b=c02877e60e3549f8a33b3a41e498b4b6;m=25ee90ad7;t=63462636f854a;x=6d3350face800769
executable:     /usr/bin/melt-7
cmdline:        /usr/bin/melt-7 -loglevel error -progress2 /tmp/kdenlive-xWVosr-1.mlt
cgroup:         0::/user.slice/user-1000.slice/user/app.slice/app-org.kde.kdenlive
rootdir:        /
uid:            1000
kernel:         6.14.4-300.fc42.x86_64
package:        mlt-7.30.0-1.fc42
runlevel:       N 5
dso_list:       /usr/bin/melt-7 mlt-7.30.0-1.fc42.x86_64 (Fedora Project) 1744816391
backtrace_rating: 4
crash_function: consumer_thread

Truncated backtrace:
Thread no. 1 (2 frames)
 #0 consumer_thread at /usr/src/debug/mlt-7.30.0-1.fc42.x86_64/src/modules/avformat/consumer_avformat.c:2425
 #2 __clone3 at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:78