FFmpeg：按語言選擇音頻流

Question

我試圖轉碼電視流，但只包含英語音頻流。我已經使用-map 0:m:language:eng流符試過，但我得到：

"Automatic encoder selection failed for output stream #0:3. Default encoder for format mpegts (codec none) is probably disabled. Please choose an encoder manually. 
Error selecting an encoder for stream 0:3" 

儘管這是包括編碼器。我嘗試了各種各樣的關於這個主題的變化，但都沒有成功。

爲一次嘗試全部輸出低於：

ffmpeg -i http://192.168.1.74:8001/1:0:1:189E:7FD:2:11A0000:0:0:0: -ignore_unknown -map 0:a -map 0:m:language:eng -map 0:v -acodec aac -vcodec libx264 -b:v 1100000 -t 00:00:30 "somethin.ts" 2>output.txt 

    Consider increasing the value for the 'analyzeduration' and 'probesize' options 
[mpegts @ 03db7b60] Could not find codec parameters for stream 17 (Unknown: none ([11][0][0][0]/0x000B)): unknown codec 
Consider increasing the value for the 'analyzeduration' and 'probesize' options 
[mpegts @ 03db7b60] Could not find codec parameters for stream 18 (Unknown: none ([11][0][0][0]/0x000B)): unknown codec 
Consider increasing the value for the 'analyzeduration' and 'probesize' options 
Input #0, mpegts, from 'http://192.168.1.74:8001/1:0:1:189E:7FD:2:11A0000:0:0:0:': 
    Duration: N/A, start: 23690.732933, bitrate: N/A 
    Program 6321 
    Program 6322 
    Program 6338 
    Program 6301 
    Program 6302 
    Stream #0:0[0x13ec]: Video: mpeg2video (Main) ([2][0][0][0]/0x0002), yuv420p(tv, top first), 720x576 [SAR 64:45 DAR 16:9], 25 fps, 25 tbr, 90k tbn, 50 tbc 
    Stream #0:1[0x13ee](NAR): Audio: mp2 ([3][0][0][0]/0x0003), 48000 Hz, stereo, s16p, 224 kb/s 
    Stream #0:2[0x13ed](eng): Audio: mp2 ([3][0][0][0]/0x0003), 48000 Hz, stereo, s16p, 224 kb/s 
    Stream #0:3[0x13ef](eng,eng): Subtitle: dvb_teletext ([6][0][0][0]/0x0006) 
    Stream #0:4[0x13f0](eng): Subtitle: dvb_subtitle ([6][0][0][0]/0x0006) 
    Stream #0:5[0xf04]: Unknown: none ([5][0][0][0]/0x0005) 
    Stream #0:6[0xf03]: Unknown: none ([5][0][0][0]/0x0005) 
    Stream #0:7[0xf02]: Unknown: none ([5][0][0][0]/0x0005) 
    Stream #0:8[0xf01]: Unknown: none ([5][0][0][0]/0x0005) 
    Stream #0:9[0xf00]: Unknown: none ([5][0][0][0]/0x0005) 
    Stream #0:10[0x92a]: Unknown: none ([5][0][0][0]/0x0005) 
    Stream #0:11[0x913]: Unknown: none ([5][0][0][0]/0x0005) 
    Stream #0:12[0x912]: Unknown: none ([5][0][0][0]/0x0005) 
    Stream #0:13[0x911]: Unknown: none ([5][0][0][0]/0x0005) 
    Stream #0:14[0x919]: Unknown: none ([5][0][0][0]/0x0005) 
    Stream #0:15[0xf09]: Unknown: none ([11][0][0][0]/0x000B) 
    Stream #0:16[0xf08]: Unknown: none ([11][0][0][0]/0x000B) 
    Stream #0:17[0xf07]: Unknown: none ([11][0][0][0]/0x000B) 
    Stream #0:18[0xf06]: Unknown: none ([11][0][0][0]/0x000B) 
    Program 6318 
    Program 6390 
    Program 6391 
    Program 6351 
    Program 6361 
    Program 6306 
    Program 6341 
Automatic encoder selection failed for output stream #0:3. Default encoder for format mpegts (codec none) is probably disabled. Please choose an encoder manually. 
Error selecting an encoder for stream 0:3 

如何做到這一點的任何想法。我不能用數字指定流，因爲我想將它用於許多電視流，而且順序通常是不同的。

由於

Answer 1

輸出流0:3是基於圖像的字幕流。由於您尚未爲字幕指定編碼器，因此ffm​​peg正在嘗試挑選一個並失敗，因爲它沒有基於圖像的字幕編碼器。您可以複製或刪除流。

ffmpeg -i http://192.168.1.74:8001/1:0:1:189E:7FD:2:11A0000:0:0:0: -ignore_unknown -c copy -map 0:a -map 0:m:language:eng -map 0:v -acodec aac -vcodec libx264 -b:v 1100000 -t 00:00:30 "somethin.ts" 2>output.txt 

---

當然，你的主要目的是通過語言映射只有音頻流。您的命令將映射兩次視頻，因爲它被標記爲英語。

爲了避免這種情況，你可以使用兩個ffmpeg的命令：

ffmpeg -i http://192.168.1.74:8001/1:0:1:189E:7FD:2:11A0000:0:0:0: -ignore_unknown -c copy -map 0:v:0 -map 0:m:language:eng -f mpegts - | ffmpeg -f mpegts -i - -map 0:v:0 -map 0:a:0 -c:a aac -c:v libx264 -b:v 1.1M out.ts