Changes between Version 65 and Version 66 of Encode/HighQualityAudio
- Timestamp:
- Oct 6, 2024, 6:27:56 AM (20 months ago)
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Encode/HighQualityAudio
v65 v66 10 10 == Generation loss == 11 11 12 Transcoding from a lossy format like [[Encoding VBR (Variable Bit Rate) mp3 audio|MP3]], [[AACEncodingGuide|AAC]], Vorbis, Opus, WMA, etc. to the same or different lossy format might degrade the audio quality even if the bitrate stays the same (or higher). This quality degradation might not be audible to you but it might be audible to others.[[BR]] 12 Transcoding from a lossy format like [[Encoding VBR (Variable Bit Rate) mp3 audio|MP3]], [[AACEncodingGuide|AAC]], Vorbis, Opus, WMA, etc. to the same or different lossy format might degrade the audio quality even if the bitrate stays the same (or higher). This quality degradation might not be audible to you but it might be audible to others. 13 13 14 This post on hydrogenaudio.org demonstrates what will happen if you re-encode a file 100 times: [[http://www.hydrogenaud.io/forums/index.php?showtopic=100067]] 14 15 … … 67 68 The highest quality internal/native encoder available in FFmpeg without any external libraries is aac.[[BR]] 68 69 69 Please note it is '''not recommended''' to use the experimental `vorbis` for Vorbis encoding; use `libvorbis` instead.[[BR]] 70 Please note that `wmav1` and `wmav2` don't seem to be able to reach transparency at any given bitrate.[[BR]] 70 Please note: 71 - it is '''not recommended''' to use the experimental `vorbis` for Vorbis encoding; use `libvorbis` instead. 72 - `wmav1` and `wmav2` don't seem to be able to reach transparency at any given bitrate. 71 73 72 74 == Container formats == … … 106 108 ffmpeg -i input.wav -c:a aac -b:a 128k output.m4a 107 109 }}} 108 - '''libtwolame''' – usable range ≥ 192Kbps. Recommended range ≥ 256Kbps [[BR]]110 - '''libtwolame''' – usable range ≥ 192Kbps. Recommended range ≥ 256Kbps 109 111 - '''mp2''' – usable range ≥ 320Kbps. Recommended range ≥ 320Kbps[[BR]] 110 112 111 113 The '''vorbis''' and '''wmav1/wmav2''' encoders are not worth using.[[BR]] 112 114 The '''wmav1/wmav2''' encoder '''does not reach transparency at any bitrate'''.[[BR]] 113 The '''vorbis''' encoder does not use the bitrate specified in FFmpeg. On some samples it does sound reasonable, but the bitrate is very high.[[BR]][[BR]] 115 The '''vorbis''' encoder does not use the bitrate specified in FFmpeg. On some samples it does sound reasonable, but the bitrate is very high. 116 114 117 To calculate the bitrate to use for multi-channel audio: (bitrate for stereo) x (channels / 2).[[BR]] 115 118 Example for 5.1 (6 channels) Vorbis audio: 128Kbps x (6 / 2) = 384Kbps[[BR]]
