Ffmpeg和ff探头没有在m3u8文件中显示字幕流

Question

我正在尝试从一个mp4播放列表文件(在简单的HLS)中获得一个带有音频、视频和字幕的m3u8视频。

我成功地提取了视频和音频流，因为它们相对容易:根据ff探针的说法，输入m3u8包含3个不同的程序，而第三个程序(称为程序2)是我所需要的，因为它包含最高质量的视频和英语最高质量的音频。

所以，我真正要做的是

ffmpeg -i "blahblah.m3u8" -c copy -map 0:p:2:v:0 -map 0:p:2:a:m:language:eng -map 0:s:0 "output.mp4"

这意味着:为第三个节目(索引2)选择第一个视频流，从同一个第三个节目(索引2)中选择英语音频流。

我的问题是:我似乎找不到这两个字幕流。m3u8有两个字幕:英语和西班牙语，你可以在m3u8本身看到

#EXTM3U
# Created with Bento4 mp4-hls.py version 1.2.0r637

#EXT-X-VERSION:4

# Subtitles
#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="subtitles",NAME="English",LANGUAGE="en",URI="subtitles/en/subtitles.m3u8"
#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="subtitles",NAME="Español",LANGUAGE="es",URI="subtitles/es/subtitles.m3u8"

# Audio
#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="audio_aac",NAME="Français",LANGUAGE="fra",AUTOSELECT=YES,DEFAULT=YES,URI="audio/aac/fra/stream.m3u8"
#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="audio_aac",NAME="English",LANGUAGE="eng",AUTOSELECT=YES,URI="audio/aac/eng/stream.m3u8"

# Media Playlists
#EXT-X-STREAM-INF:AVERAGE-BANDWIDTH=2198120,BANDWIDTH=2416640,CODECS="avc1.4D401F,mp4a.40.2",RESOLUTION=1280x720,AUDIO="audio_aac",SUBTITLES="subtitles"
media-1/stream.m3u8
#EXT-X-STREAM-INF:AVERAGE-BANDWIDTH=1001663,BANDWIDTH=1102896,CODECS="avc1.42C01E,mp4a.40.2",RESOLUTION=640x360,AUDIO="audio_aac",SUBTITLES="subtitles"
media-2/stream.m3u8
#EXT-X-STREAM-INF:AVERAGE-BANDWIDTH=4007581,BANDWIDTH=4391894,CODECS="avc1.4D4029,mp4a.40.2",RESOLUTION=1920x1080,AUDIO="audio_aac",SUBTITLES="subtitles"
media-3/stream.m3u8

我认为这很容易:我添加了一个-map 0:s:0来获得第一个字幕，但是ffmpeg告诉我没有这样的流。

然后我跑了一下，告诉我他没有字幕流：

ffprobe "blahblah.m3u8" -show_streams -select_streams s

您可以在这里找到ff探针命令显示的所有流。。有很多的视频和音频流，但没有字幕流。

为什么ffmpeg和ff探头找不到字幕流呢？是因为它们是在不同的m3u8播放列表文件中被分割的吗？

Answer 1

$sw = [Diagnostics.Stopwatch]::StartNew()
$files = Get-ChildItem ${Get-Location}
$loco = Get-Location
$p1 = Join-Path -Path $loco -ChildPath "/out"
New-Item -ItemType Directory -Force -Path $p1



function lnCodeTransform {
    param( $String )
    switch ($String)
    {
        "jpn" {"jp"}
        "eng" {"en"}
        "esp" {"es"}
        "fra" {"fr"}
        "deu" {"de"}
        default {$String}
    }
}


function lnNameTransform {
    param( $String )
    switch ($String)
    {
        "jpn" {"Japanese"}
        "eng" {"English"}
        "esp" {"Spanish"}
        "fra" {"French"}
        "deu" {"German"}
        default {$String}
    }
}


foreach ($f in $files){ 
    if ($f.Name -eq "out"){
        continue;
    }
    $p2 = Join-Path -Path $loco -ChildPath "/out/" | Join-Path -ChildPath $f
    New-Item -ItemType Directory -Force -Path $p2/audio
    New-Item -ItemType Directory -Force -Path $p2/video
    New-Item -ItemType Directory -Force -Path $p2/subtitle
    $sb = [System.Text.StringBuilder]::new();
    [void]$sb.AppendLine( '#EXTM3U' )
    [void]$sb.AppendLine( '#EXT-X-VERSION:3' )
    #[void]$sb.AppendLine( '#EXT-X-STREAM-INF:BANDWIDTH=800000,RESOLUTION=640x360' )
    #[void]$sb.AppendLine( '360p.m3u8' )
    

    New-Item -ItemType Directory -Force -Path $p2
    $resStr = ffprobe -v error -select_streams v:0 -show_entries stream=height -of csv=s=x:p=0 $f.FullName;
    $res = [convert]::ToInt32($resStr)
    $audioTracks = ffprobe $f.FullName -show_entries stream=index:stream_tags=language,title -select_streams a -of compact=p=0:nk=1 
    $audioTracks = $audioTracks.split("\r")
    foreach($audio in $audioTracks) {
        $splited = $audio.split("|");
        $ID = $splited[0]
        $audioName = $splited[1];
        $title = $splited[2];
        ffmpeg -i $f.FullName -ss 0 -y -map 0:$ID -start_number 0 -acodec aac -b:a 320k -ac 2 -f segment -segment_time 10 -segment_list_size 0 -segment_list out/$f/audio/audio_"$ID.m3u8" -segment_format mpegts out/$f/audio/"audio_$ID""_%d.ts"
        $name = lnNameTransform($audioName)
        $code = lnCodeTransform($audioName)
        [void]$sb.AppendLine( "#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID=`"aac`",LANGUAGE=`"$code`",NAME=`"$name ($title)`",DEFAULT=NO,AUTOSELECT=NO,URI=`"audio/audio_$ID.m3u8`"" )
    }
    $subTracks = ffprobe $f.FullName -show_entries stream=index:stream_tags=language,title -select_streams s -of compact=p=0:nk=1 
    $subTracks = $subTracks.split("\r")
    foreach($subtitle in $subTracks) {
        $splited = $subtitle.split("|");
        $ID = $splited[0];
        $subName = $splited[1];
        $title = $splited[2];
        ffmpeg -i $f.FullName -ss 0 -map 0:$ID -f segment -segment_time 10 -segment_list_size 0 -segment_list out/$f/subtitle/sub_"$ID.m3u8" -segment_format webvtt -scodec webvtt out/$f/subtitle/"sub_$ID%d.vtt"
        $name = lnNameTransform($subName)
        $code = lnCodeTransform($subName)
        [void]$sb.AppendLine( "#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID=`"subs`",LANGUAGE=`"$code`",NAME=`"$name ($title)`",FORCED=NO,AUTOSELECT=NO,URI=`"subtitle/sub_$ID.m3u8`"" )
    }

    [void]$sb.AppendLine( '#EXT-X-STREAM-INF:BANDWIDTH=1400000,CODECS="avc1.4d4015,mp4a.40.2",RESOLUTION=842x480,AUDIO="aac",SUBTITLES="subs"' )
    [void]$sb.AppendLine( 'video/480p.m3u8' )
    #ffmpeg -i $f.FullName -c:a copy -vf scale=w=640:h=360:force_original_aspect_ratio=decrease -c:a aac -ar 48000  -rc cqp -qp_p 0 -qp_i 1 -profile:v main -crf 20 -sc_threshold 0 -g 48 -keyint_min 48 -hls_time 4 -hls_playlist_type vod  -b:v 800k -maxrate 856k -bufsize 1200k -b:a 96k -hls_segment_filename out/$f/360p_%03d.ts out/$f/360p.m3u8 -vf scale=w=842:h=480:force_original_aspect_ratio=decrease -c:a aac -ar 48000 -gpu 1 -c:v h264_amf -rc cqp -qp_p 0 -qp_i 1 -profile:v main -crf 20 -sc_threshold 0 -g 48 -keyint_min 48 -hls_time 4 -hls_playlist_type vod -b:v 1400k -maxrate 1498k -bufsize 2100k -b:a 128k -hls_segment_filename out/$f/480p_%03d.ts out/$f/480p.m3u8 -vf  scale=w=1280:h=720:force_original_aspect_ratio=decrease -c:a aac -ar 48000 -gpu 1 -c:v h264_amf -rc cqp -qp_p 0 -qp_i 1 -profile:v main -crf 20 -sc_threshold 0 -g 48 -keyint_min 48 -hls_time 4 -hls_playlist_type vod -b:v 2800k -maxrate 2996k -bufsize 4200k -b:a 128k -hls_segment_filename out/$f/720p_%03d.ts out/$f/720p.m3u8 -vf  scale=w=1920:h=1080:force_original_aspect_ratio=decrease -c:a aac -ar 48000 -gpu 1 -c:v h264_amf -rc cqp -qp_p 0 -qp_i 1 -profile:v main -crf 20 -sc_threshold 0 -g 48 -keyint_min 48 -hls_time 4 -hls_playlist_type vod -b:v 5000k -maxrate 5350k -bufsize 7500k -b:a 192k -hls_segment_filename out/$f/1080p_%03d.ts out/$f/1080p.m3u8
    #ffmpeg -hwaccel auto -hwaccel_device 0 -i $f.FullName -c:v h264 -profile:v main -pix_fmt yuv420p -c:a aac -filter:v scale=360:640 -ar 48000  -rc cqp -qp_p 0 -qp_i 1 -profile:v main -crf 23 -sc_threshold 0 -g 48 -b:v 800k -maxrate 856k -bufsize 1200k -b:a 96k  -keyint_min 4 -start_number 0 -hls_time 10 -hls_playlist_type vod  -hls_list_size 0 -f hls -hls_segment_filename out/$f/360p_%03d.ts out/$f/360p.m3u8 
    #ffmpeg -hwaccel auto -hwaccel_device 0 -i $f.FullName -c:v h264 -profile:v main -pix_fmt yuv420p -c:a aac -filter:v scale=360:640 -start_number 0 -hls_time 10 -hls_list_size 0 -f hls -hls_segment_filename out/$f/360p_%03d.ts out/$f/360p.m3u8 
    #ffmpeg -i $f.FullName -c:v h264 -crf 23 -b:v 1200k -minrate 500k -maxrate 2100k -profile:v main -pix_fmt yuv420p -y -filter:v scale=-2:480 -map 0:v -start_number 0 -hls_time 10 -hls_list_size 0 -f hls -hls_segment_filename out/$f/video/480p_%03d.ts out/$f/video/480p.m3u8
    ffmpeg -i $f.FullName -c:v h264_qsv -preset slow -global_quality 30 -look_ahead 1 -profile:v main -level:v 4.1 -rc:v vbr_hq -rc-lookahead:v 32 -pix_fmt yuv420p -y -filter:v scale=-2:480 -map 0:v -start_number 0 -hls_time 10 -hls_list_size 0 -f hls -hls_segment_filename out/$f/video/480p_%03d.ts out/$f/video/480p.m3u8
    If($res -ge 720) {
        #ffmpeg -i $f.FullName -c:v h264_qsv -crf 23 -b:v 2400k -minrate 1200k -maxrate 4200k -profile:v main -pix_fmt yuv420p -filter:v scale=-2:720 -map 0:v -start_number 0 -hls_time 10 -hls_list_size 0 -f hls -hls_segment_filename out/$f/video/720p_%03d.ts out/$f/video/720p.m3u8
        ffmpeg -i $f.FullName -c:v h264_qsv -preset slow -global_quality 28 -look_ahead 1 -profile:v main -level:v 4.1 -rc:v vbr_hq -rc-lookahead:v 32 -pix_fmt yuv420p -filter:v scale=-2:720 -map 0:v -start_number 0 -hls_time 10 -hls_list_size 0 -f hls -hls_segment_filename out/$f/video/720p_%03d.ts out/$f/video/720p.m3u8
        [void]$sb.AppendLine( '#EXT-X-STREAM-INF:BANDWIDTH=2800000,CODECS="avc1.4d4015,mp4a.40.2",RESOLUTION=1280x720,AUDIO="aac",SUBTITLES="subs"' )
        [void]$sb.AppendLine( 'video/720p.m3u8' )
    }   
    If($res -ge 900) {
        #ffmpeg -i $f.FullName -c:v h264 -crf 30 -b:v 4800k -minrate 2000k -maxrate 8400k -profile:v main -pix_fmt yuv420p -filter:v scale=-2:1080 -map 0:v -start_number 0 -hls_time 10 -hls_list_size 0 -f hls -hls_segment_filename out/$f/video/1080p_%03d.ts out/$f/video/1080p.m3u8
        ffmpeg -i $f.FullName -c:v h264_qsv -preset slow -global_quality 26 -look_ahead 1 -profile:v main -level:v 4.1 -rc:v vbr_hq -rc-lookahead:v 32 -pix_fmt yuv420p -filter:v scale=-2:1080 -map 0:v -start_number 0 -hls_time 10 -hls_list_size 0 -f hls -hls_segment_filename out/$f/video/1080p_%03d.ts out/$f/video/1080p.m3u8

        [void]$sb.AppendLine( '#EXT-X-STREAM-INF:BANDWIDTH=5000000,CODECS="avc1.4d4015,mp4a.40.2",RESOLUTION=1920x1080,AUDIO="aac",SUBTITLES="subs"' )
        [void]$sb.AppendLine( 'video/1080p.m3u8' )
    }
    
    $p3 = Join-Path -Path $p2 -ChildPath "/index.m3u8"
    #echo $index | Out-File -Encoding UTF8 -LiteralPath $p3
    echo $sb.ToString()
    [System.IO.File]::WriteAllLines($p3, $sb.ToString().Trim().replace("`r`n", "`n"))
}
$sw.Stop()
echo $sw.Elapsed

这是我的脚本，用于将文件转换为HLS，并生成index.m3u8文件。是的，您需要编辑索引，但是它可以完成所有的工作。此外，这个脚本使用英特尔gpu。您可以删除_qsv，使其在任何CPU上工作。