Changes between Version 14 and Version 15 of Encode/HighQualityAudio


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Timestamp:
Apr 8, 2013, 9:05:26 PM (6 years ago)
Author:
llogan
Comment:

spaces, nits, comments

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  • Encode/HighQualityAudio

    v14 v15  
    44== When should I transcode audio? ==
    55
    6 Avoid transcoding from lossy to lossy if possible. Use the lossless source(if you have it) or just don't transcode by copying the source audio track.
     6Avoid transcoding from lossy to lossy if possible. Use the lossless source (if you have it) or just don't transcode by copying the source audio track.
    77
    88== Generation loss ==
    99
    10 Transcoding from a lossy format like MP3,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]]
    11 This post on hydrogenaudio.org demonstrates what will happen if you transcode a file 100 times: [[http://www.hydrogenaudio.org/forums/index.php?showtopic=100067]]
     10Transcoding from a lossy format like MP3, 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]]
     11This post on hydrogenaudio.org demonstrates what will happen if you re-encode a file 100 times: [[http://www.hydrogenaudio.org/forums/index.php?showtopic=100067]]
    1212
    1313== Copying audio tracks ==
     
    2525== Audio encoders ffmpeg can use ==
    2626
    27 ffmpeg can encode to a wide variery of audio formats.[[BR]]
     27ffmpeg can encode to a wide variety of audio formats.[[BR]]
    2828
    2929Here are some popular formats with encoders listed that ffmpeg can use:[[BR]]
     
    4545}}}
    4646
     47{{{#!comment
     48Source for above hierarchy?
     49}}}
     50
    4751The '''>=''' sign means greater or the same quality.[[BR]]
    48 Even though AAC should generally give better quality than MP3 at the same bitrates libmp3lame should give better quality output than libfaac.[[BR]]
     52Even though AAC should generally give better quality than MP3 at the same bitrates libmp3lame should give better quality output than `libfaac`.[[BR]]
    4953This list is just a general idea and there might be cases where codecs listed to the right might perform better than those listed to the left at certain bitrates. [[BR]]
    5054The highest quality internal/native encoder available in ffmpeg without any external libraries is eac3/ac3. [[BR]]
    5155
    52 Please note it is '''not recommended''' to use 'libvo_aacenc' for AAC encoding.[[BR]]
    53 Please note it is '''not recommended''' to use 'vorbis' for Vorbis encoding.[[BR]]
    54 Please note that 'wmav1 or wmav2' don't seem to be able to reach transparency at any given bitrate.[[BR]]
     56Please note it is '''not recommended''' to use `libvo_aacenc` for AAC encoding.[[BR]]
     57Please note it is '''not recommended''' to use `vorbis` for Vorbis encoding.[[BR]]
     58Please note that `wmav1` or `wmav2` don't seem to be able to reach transparency at any given bitrate.[[BR]]
     59
     60{{{#!comment
     61Please explain why it is not recommended to use these encoders or link to other wiki pages that do explain.
     62}}}
    5563
    5664== Container formats ==
    5765Only certain audio codecs will be able to fit in your target output file.
    5866||'''Container'''||'''Audio formats supported'''||
    59 ||'''MKV/MKA'''||Vorbis,MP2,MP3,LC-AAC,HE-AAC,WMAv1,WMAv2,AC3,eAC3||
    60 ||'''MP4/M4A'''||MP2,MP3,LC-AAC,HE-AAC,AC3||
    61 ||'''FLV/F4V'''||MP3,LC-AAC,HE-AAC||
    62 ||'''3GP/3G2'''||LC-AAC,HE-AAC||
    63 ||'''MPG'''||MP2,MP3||
    64 ||'''PS/TS Stream'''||MP2,MP3,LC-AAC,HE-AAC,AC3||
    65 ||'''M2TS'''||AC3,eAC3||
    66 ||'''VOB'''||MP2,AC3||
    67 ||'''RMVB'''||Vorbis,HE-AAC||
     67||'''MKV/MKA'''||Vorbis, MP2, MP3, LC-AAC, HE-AAC, WMAv1, WMAv2, AC3, eAC3||
     68||'''MP4/M4A'''||MP2, MP3, LC-AAC, HE-AAC, AC3||
     69||'''FLV/F4V'''||MP3, LC-AAC, HE-AAC||
     70||'''3GP/3G2'''||LC-AAC, HE-AAC||
     71||'''MPG'''||MP2, MP3||
     72||'''PS/TS Stream'''||MP2, MP3, LC-AAC, HE-AAC, AC3||
     73||'''M2TS'''||AC3, eAC3||
     74||'''VOB'''||MP2, AC3||
     75||'''RMVB'''||Vorbis, HE-AAC||
    6876||'''WebM'''||Vorbis||
    69 ||'''OGG'''||Vorbis,Opus||
     77||'''OGG'''||Vorbis, Opus||
    7078Please note that there are more container formats available than those listed above.
    7179
     
    8694- '''aac''' Recommended usable range '''>= 300kbps'''. Compression artifacts start becoming unnoticeable around 300Kbps[[BR]]
    8795- '''vorbis''' Recommended usable range '''>= 280kbps'''. Compression artifacts start becoming unnoticeable around 280Kbps[[BR]]
    88 - '''wmav1 or wmav2''' Recommended usable range '''>= ????kbps'''. Does not reach tranparency. Notice artifacts on every bitrate. Broken?[[BR]]
    89 - '''libvo_aacenc''' Recommended usable range '''>= ????kbps'''. Does not reach tranparency. Notice artifacts on every bitrate. Broken? [[BR]]
     96- '''wmav1 or wmav2''' Recommended usable range '''>= ????kbps'''. Does not reach transparency. Notice artifacts on every bitrate. Broken?[[BR]]
     97- '''libvo_aacenc''' Recommended usable range '''>= ????kbps'''. Does not reach transparency. Notice artifacts on every bitrate. Broken? [[BR]]
    9098----
    9199
    92 Please note Opus streams are currently not muxable in MKV containers. Only Ogg Containers are supported at the moment. MKV container support is should be available in the future[[BR]]
    93 When compatibility with hardware players doesn't matter then use libvorbis in a MKV container rather than libfaac when libfdk_aac isn't available[[BR]]
    94 When compatibility with hardware players does matter then use libmp3lame or ac3 in a MP4/MKV container rather than libfaac when libfdk_aac isn't available[[BR]]
     100Please note Opus streams are currently not muxable in MKV containers. Only Ogg Containers are supported at the moment. MKV container support should be available in the future[[BR]]
     101When compatibility with hardware players doesn't matter then use `libvorbis` in a MKV container rather than `libfaac` when `libfdk_aac` isn't available[[BR]]
     102When compatibility with hardware players does matter then use libmp3lame or ac3 in a MP4/MKV container rather than `libfaac` when `libfdk_aac` isn't available[[BR]]
    95103Transparency means the encoded audio sounds indistinguishable from the audio in the source file.[[BR]]
    96104[[BR]]