Created attachment 183282 [details] Screenshot of Kdenlive timeline, showing a difference between embedded audio thumbnail and extracted audio thumbnail. SUMMARY When working with a video file that has audio delay metadata, the audio thumbnail does not account for that delay, although playback does. STEPS TO REPRODUCE 1. Import a video with delay metadata 2. Drag video onto editing timeline OBSERVED RESULT Audio thumbnail lags behind playback audio by the amount of time specified in the file's metadata. EXPECTED RESULT Audio thumbnail reflects the timing of audio during actual playback. SOFTWARE/OS VERSIONS Linux/KDE Plasma: 6.15.6 Qt Version: 6.9.1-4 ADDITIONAL INFORMATION Below is the full MediaInfo details for the file shown in the attached screenshot. Of note is the value marked "Source_Delay": General Count : 359 Count of stream of this kind : 1 Kind of stream : General Kind of stream : General Stream identifier : 0 Inform : MPEG-4 (Base Media): 5.63 GiB, 1 h 45 min Count of video streams : 1 Count of audio streams : 1 Video_Format_List : AV1 Video_Format_WithHint_List : AV1 Codecs Video : AV1 Audio_Format_List : AAC LC Audio_Format_WithHint_List : AAC LC Audio codecs : AAC LC Audio_Channels_Total : 2 Complete name : /home/wheels/Videos/NormalOut.mp4 Folder name : /home/wheels/Videos File name extension : NormalOut.mp4 File name : NormalOut File extension : mp4 Format : MPEG-4 Format : MPEG-4 Format/Extensions usually used : braw mov mp4 m4v m4a m4b m4p m4r 3ga 3gpa 3gpp 3gp 3gpp2 3g2 k3g jpm jpx mqv ismv isma ismt f4a f4b f4v Commercial name : MPEG-4 Format profile : Base Media Internet media type : video/mp4 Codec ID : isom Codec ID : isom (isom/av01/iso2/mp41) Codec ID/Url : http://www.apple.com/quicktime/download/standalone.html CodecID_Compatible : isom/av01/iso2/mp41 File size : 6049027444 File size : 5.63 GiB File size : 6 GiB File size : 5.6 GiB File size : 5.63 GiB File size : 5.634 GiB Duration : 6334750 Duration : 1 h 45 min Duration : 1 h 45 min 34 s 750 ms Duration : 1 h 45 min Duration : 01:45:34.750 Duration : 01:45:34:43 Duration : 01:45:34.750 (01:45:34:43) Overall bit rate mode : VBR Overall bit rate mode : Variable Overall bit rate : 7639168 Overall bit rate : 7 639 kb/s Frame rate : 60.000 Frame rate : 60.000 FPS Frame count : 380083 HeaderSize : 32 DataSize : 6039565675 FooterSize : 9461737 IsStreamable : No File last modification date : 2025-07-13 22:32:45 UTC File last modification date (local) : 2025-07-13 18:32:45 Writing application : Lavf61.7.100 Writing application : Lavf61.7.100 Video Count : 391 Count of stream of this kind : 1 Kind of stream : Video Kind of stream : Video Stream identifier : 0 StreamOrder : 0 Inform : 7 509 kb/s, 1280*960 (4:3), at 60.000 FPS, AV1 (Main@L5.2) ID : 1 ID : 1 Format : AV1 Format : AV1 Format/Info : AOMedia Video 1 Format/Url : http://aomedia.org/ Commercial name : AV1 Format profile : Main@L5.2 Codec ID : av01 Duration : 6334717 Duration : 1 h 45 min Duration : 1 h 45 min 34 s 717 ms Duration : 1 h 45 min Duration : 01:45:34.717 Duration : 01:45:34:43 Duration : 01:45:34.717 (01:45:34:43) Bit rate : 7508752 Bit rate : 7 509 kb/s Width : 1280 Width : 1 280 pixels Height : 960 Height : 960 pixels Sampled_Width : 1280 Sampled_Height : 960 Pixel aspect ratio : 1.000 Display aspect ratio : 1.333 Display aspect ratio : 4:3 Rotation : 0.000 Frame rate mode : CFR Frame rate mode : Constant Frame rate : 60.000 Frame rate : 60.000 FPS FrameRate_Num : 60 FrameRate_Den : 1 Frame count : 380083 Color space : YUV Chroma subsampling : 4:2:0 Chroma subsampling : 4:2:0 Bit depth : 8 Bit depth : 8 bits Scan type : Progressive Scan type : Progressive Bits/(Pixel*Frame) : 0.102 Stream size : 5945727524 Stream size : 5.54 GiB (98%) Stream size : 6 GiB Stream size : 5.5 GiB Stream size : 5.54 GiB Stream size : 5.537 GiB Stream size : 5.54 GiB (98%) Proportion of this stream : 0.98292 Writing library : Lavc61.19.101 av1_amf Writing library : Lavc61.19.101 av1_amf colour_description_present : Yes colour_description_present_Source : Container Color range : Limited colour_range_Source : Container / Stream Color primaries : BT.709 colour_primaries_Source : Container Transfer characteristics : BT.709 transfer_characteristics_Source : Container Matrix coefficients : BT.709 matrix_coefficients_Source : Container Codec configuration box : av1C Audio Count : 287 Count of stream of this kind : 1 Kind of stream : Audio Kind of stream : Audio Stream identifier : 0 StreamOrder : 1 Inform : 48.0 kHz, 2 channels, AAC LC ID : 2 ID : 2 Format : AAC Format : AAC LC Format/Info : Advanced Audio Codec Low Complexity Commercial name : AAC Format settings, SBR : No (Explicit) Format settings, SBR : No (Explicit) Format_AdditionalFeatures : LC Codec ID : mp4a-40-2 Duration : 6334750 Duration : 1 h 45 min Duration : 1 h 45 min 34 s 750 ms Duration : 1 h 45 min Duration : 01:45:34.750 Duration : 01:45:34.750 Source duration : 6334294 Source duration : 1 h 45 min Source duration : 1 h 45 min 34 s 294 ms Source duration : 1 h 45 min Source duration : 01:45:34.294 Source duration : 01:45:34.294 Bit rate mode : VBR Bit rate mode : Variable Nominal bit rate : 118514 Nominal bit rate : 119 kb/s Maximum bit rate : 128000 Maximum bit rate : 128 kb/s Channel(s) : 2 Channel(s) : 2 channels Channel positions : Front: L R Channel positions : 2/0/0 Channel layout : L R Samples per frame : 1024 Sampling rate : 48000 Sampling rate : 48.0 kHz Samples count : 304068000 Frame rate : 46.875 Frame rate : 46.875 FPS (1024 SPF) Frame count : 296941 Source frame count : 296920 Compression mode : Lossy Compression mode : Lossy Source stream size : 93838135 Source stream size : 89.5 MiB (2%) Source stream size : 89 MiB Source stream size : 89 MiB Source stream size : 89.5 MiB Source stream size : 89.49 MiB Source stream size : 89.5 MiB (2%) Source_StreamSize_Proportion : 0.01551 Default : Yes Default : Yes Alternate group : 1 Alternate group : 1 Source_Delay : 456 Source_Delay_Source : Container
Additional information can be found in the forum thread this was first reported to: https://discuss.kde.org/t/audio-thumbnail-lagging-behind-actual-audio/37027
Thanks for your report. Could you please also include the output of this command in a terminal;: ffmpeg -i yourvideo.mp4 or a short sample file reproducing this problem ?
Created attachment 183286 [details] Kdenlive project showcasing audio thumbnail delay
ffmpeg outputs the following on the original file: ffmpeg version n7.1.1 Copyright (c) 2000-2025 the FFmpeg developers built with gcc 15.1.1 (GCC) 20250425 configuration: --prefix=/usr --disable-debug --disable-static --disable-stripping --enable-amf --enable-avisynth --enable-cuda-llvm --enable-lto --enable-fontconfig --enable-frei0r --enable-gmp --enable-gnutls --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libdav1d --enable-libdrm --enable-libdvdnav --enable-libdvdread --enable-libfreetype --enable-libfribidi --enable-libglslang --enable-libgsm --enable-libharfbuzz --enable-libiec61883 --enable-libjack --enable-libjxl --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libplacebo --enable-libpulse --enable-librav1e --enable-librsvg --enable-librubberband --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libv4l2 --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpl --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-libzimg --enable-libzmq --enable-nvdec --enable-nvenc --enable-opencl --enable-opengl --enable-shared --enable-vapoursynth --enable-version3 --enable-vulkan libavutil 59. 39.100 / 59. 39.100 libavcodec 61. 19.101 / 61. 19.101 libavformat 61. 7.100 / 61. 7.100 libavdevice 61. 3.100 / 61. 3.100 libavfilter 10. 4.100 / 10. 4.100 libswscale 8. 3.100 / 8. 3.100 libswresample 5. 3.100 / 5. 3.100 libpostproc 58. 3.100 / 58. 3.100 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'NormalOut.mp4': Metadata: major_brand : isom minor_version : 512 compatible_brands: isomav01iso2mp41 encoder : Lavf61.7.100 Duration: 01:45:34.75, start: 0.000000, bitrate: 7639 kb/s Stream #0:0[0x1](und): Video: av1 (libdav1d) (Main) (av01 / 0x31307661), yuv420p(tv, bt709, progressive), 1280x960, 7508 kb/s, SAR 1:1 DAR 4:3, 60 fps, 60 tbr, 15360 tbn (default) Metadata: handler_name : VideoHandler vendor_id : [0][0][0][0] encoder : Lavc61.19.101 av1_amf Stream #0:1[0x2](und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 118 kb/s (default) Metadata: handler_name : SoundHandler vendor_id : [0][0][0][0]
Git commit 0369eebedf368d02034d92105d01a2996787f78a by Jean-Baptiste Mardelle. Committed on 17/07/2025 at 10:53. Pushed by mardelle into branch 'master'. Audio thumbnails for files with an audio delay are not correctly geenrated with the libav generator M +8 -0 src/jobs/audiolevels/generators.cpp https://invent.kde.org/multimedia/kdenlive/-/commit/0369eebedf368d02034d92105d01a2996787f78a
Git commit 79d454b1aca8100d8d9578b466f693bb0c6e9779 by Jean-Baptiste Mardelle. Committed on 17/07/2025 at 10:55. Pushed by mardelle into branch 'release/25.08'. Audio thumbnails for files with an audio delay are not correctly geenrated with the libav generator M +8 -0 src/jobs/audiolevels/generators.cpp https://invent.kde.org/multimedia/kdenlive/-/commit/79d454b1aca8100d8d9578b466f693bb0c6e9779