Download video and audio, convert audio only and merge previously downloaded video and converted audio

Checklist

• I’m asking a question and not reporting a bug/feature request
• I’ve looked through the README
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• I’ve searched the bugtracker for similar questions including closed ones

Question

For example, when I download this video from YouTube and select the 299+251 formats they merge into MKV because of format incompatibility (avc1.64001e+opus), but I need the video and audio to be in the MP4 container, i.e. convert from opus to aac the audio since the video codec is compatible with the container.

How can I leave the video alone (not reencode it), convert only the audio to aac and then merge the unmodified video and the converted audio? I have tried with the --audio format or -x option but I get different outputs that don’t solve my problem.

Verbose log

No response

[pukkandan]

try this

❯ yt-dlp test:youtube -f 137+251 -v --recode mp4 --ppa "VideoConvertor:-vcodec copy"
[debug] Command-line config: ['test:youtube', '-f', '137+251', '-v', '--recode', 'mp4', '--ppa', 'VideoConvertor:-vcodec copy']
[debug] Encodings: locale cp65001, fs utf-8, out utf-8, err utf-8, pref cp65001
[debug] yt-dlp version 2022.03.08.1 [c0c2c57d3] (source)
[debug] Lazy loading extractors is disabled
[debug] Plugins: ['SamplePluginIE', 'SamplePluginPP']
[debug] Git HEAD: e4b98809c
[debug] Python version 3.10.3 (CPython 64bit) - Windows-10-10.0.22000-SP0
[debug] exe versions: ffmpeg N-105465-gbedb4bac1c-20220206 (fdk,setts), ffprobe N-105465-gbedb4bac1c-20220206, phantomjs 2.1.1
[debug] Optional libraries: brotli, Cryptodome, mutagen, sqlite, websockets
[debug] Proxy map: {}
[debug] [TestURL] Extracting URL: test:youtube
[TestURL] Test URL: https://www.youtube.com/watch?v=BaW_jenozKc&t=1s&end=9
[debug] [youtube] Extracting URL: https://www.youtube.com/watch?v=BaW_jenozKc&t=1s&end=9
[youtube] BaW_jenozKc: Downloading webpage
[youtube] BaW_jenozKc: Downloading android player API JSON
[debug] Sort order given by extractor: quality, res, fps, hdr:12, source, codec:vp9.2, lang, proto
[debug] Formats sorted by: hasvid, ie_pref, quality, res, fps, hdr:12(7), source, vcodec:vp9.2(10), acodec, lang, proto, filesize, fs_approx, tbr, vbr, abr, asr, vext, aext, hasaud, id
[info] BaW_jenozKc: Downloading 1 format(s): 137+251
WARNING: Requested formats are incompatible for merge and will be merged into mkv
[debug] Invoking downloader on "https://rr3---sn-gwpa-jjwe.googlevideo.com/videoplayback?expire=1647642355&ei=k7I0YsO4AbairtoPvu2A8Ac&ip=2405%3A201%3Af003%3Abaf6%3A2156%3A189f%3Ad8cf%3A3de1&id=o-AK7pVqZVSoRfCXTtLDjhnipt5Jgh4pNuMBb2Hy-a-Yin&itag=137&source=youtube&requiressl=yes&mh=Rf&mm=31%2C29&mn=sn-gwpa-jjwe%2Csn-gwpa-h55e7&ms=au%2Crdu&mv=m&mvi=3&pcm2cms=yes&pl=47&initcwndbps=170000&vprv=1&mime=video%2Fmp4&gir=yes&clen=2208750&dur=9.800&lmt=1387961822987808&mt=1647620221&fvip=1&keepalive=yes&fexp=24001373%2C24007246&c=ANDROID&sparams=expire%2Cei%2Cip%2Cid%2Citag%2Csource%2Crequiressl%2Cvprv%2Cmime%2Cgir%2Cclen%2Cdur%2Clmt&sig=AOq0QJ8wRQIgBo_cb_vZSIe__R438WndEyyTp8yjPyKOfLuJgbllGyUCIQCEaPDDjGfafuUKx848WHssD4Two2vq1sDiZhI3Haz8Iw%3D%3D&lsparams=mh%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpcm2cms%2Cpl%2Cinitcwndbps&lsig=AG3C_xAwRQIgIMsfTWkr12pqaCnTbCQhLwrSF8X9XFWTc1Xu9UUDZ2MCIQCWAsxdK7fKqK06V9YsPLmWNdeKyktxU_HZlhfnSdtP8g%3D%3D"
[download] Destination: youtube-dl test video ''_ä↭𝕐  [BaW_jenozKc].f137.mp4
[download] 100% of 2.11MiB in 00:00
[debug] Invoking downloader on "https://rr3---sn-gwpa-jjwe.googlevideo.com/videoplayback?expire=1647642355&ei=k7I0YsO4AbairtoPvu2A8Ac&ip=2405%3A201%3Af003%3Abaf6%3A2156%3A189f%3Ad8cf%3A3de1&id=o-AK7pVqZVSoRfCXTtLDjhnipt5Jgh4pNuMBb2Hy-a-Yin&itag=251&source=youtube&requiressl=yes&mh=Rf&mm=31%2C29&mn=sn-gwpa-jjwe%2Csn-gwpa-h55e7&ms=au%2Crdu&mv=m&mvi=3&pcm2cms=yes&pl=47&initcwndbps=170000&vprv=1&mime=audio%2Fwebm&gir=yes&clen=142292&dur=9.841&lmt=1506055557712479&mt=1647620221&fvip=1&keepalive=yes&fexp=24001373%2C24007246&c=ANDROID&sparams=expire%2Cei%2Cip%2Cid%2Citag%2Csource%2Crequiressl%2Cvprv%2Cmime%2Cgir%2Cclen%2Cdur%2Clmt&sig=AOq0QJ8wRQIhAIuPfjfefKuluMaXGWiSnyNYyY9eaVP_Rkp6RyPhtG-xAiAsTbomG4wy4tWvKylyCtLJV_dJj9IJKTopUA-R5PMyFA%3D%3D&lsparams=mh%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpcm2cms%2Cpl%2Cinitcwndbps&lsig=AG3C_xAwRQIgIMsfTWkr12pqaCnTbCQhLwrSF8X9XFWTc1Xu9UUDZ2MCIQCWAsxdK7fKqK06V9YsPLmWNdeKyktxU_HZlhfnSdtP8g%3D%3D"
[download] Destination: youtube-dl test video ''_ä↭𝕐  [BaW_jenozKc].f251.webm
[download] 100% of 138.96KiB in 00:00
[Merger] Merging formats into "youtube-dl test video ''_ä↭𝕐  [BaW_jenozKc].mkv"
[debug] ffmpeg command line: ffmpeg -y -loglevel "repeat+info" -i "file:youtube-dl test video ''_ä↭𝕐  [BaW_jenozKc].f137.mp4" -i "file:youtube-dl test video ''_ä↭𝕐  [BaW_jenozKc].f251.webm" -c copy -map "0:v:0" -map "1:a:0" -movflags "+faststart" "file:youtube-dl test video ''_ä↭𝕐  [BaW_jenozKc].temp.mkv"
Deleting original file youtube-dl test video ''_ä↭𝕐  [BaW_jenozKc].f251.webm (pass -k to keep)
Deleting original file youtube-dl test video ''_ä↭𝕐  [BaW_jenozKc].f137.mp4 (pass -k to keep)
[VideoConvertor] Converting video from mkv to mp4; Destination: youtube-dl test video ''_ä↭𝕐  [BaW_jenozKc].mp4
[debug] ffmpeg command line: ffmpeg -y -loglevel "repeat+info" -i "file:youtube-dl test video ''_ä↭𝕐  [BaW_jenozKc].mkv" -movflags "+faststart" -vcodec copy "file:youtube-dl test video ''_ä↭𝕐  [BaW_jenozKc].mp4"
Deleting original file youtube-dl test video ''_ä↭𝕐  [BaW_jenozKc].mkv (pass -k to keep)

[megapro17]

No, just download compiled binary https://github.com/megapro17/FFmpeg-Builds/releases/tag/latest