h.265 encoding with ffmpeg, which preset question
I'm using ffmpeg on the command line to encode video from a QuickTime ProRes 4444p DCI-resolution source to h.265, y420p. It's working just fine, but I noticed something very odd: If I change nothing but the preset, the file size goes down as the encoding speed goes up:
Preset and resulting file size:
- veryslow: 5814379
- slower: 5812081
- slow: 5640739
- medium: 5455779
- fast: 5164506
- faster: 5099833
- veryfast: 5108824 (file size starts going up from this point)
My question is: This is rather the opposite from what I'd expect. Am I missing something obvious?
ffmpeg h.265
asked Nov 26 '18 at 20:58
ChristopheChristophe
1,36411524
add a comment |
I'm using ffmpeg on the command line to encode video from a QuickTime ProRes 4444p DCI-resolution source to h.265, y420p. It's working just fine, but I noticed something very odd: If I change nothing but the preset, the file size goes down as the encoding speed goes up:
Preset and resulting file size:
- veryslow: 5814379
- slower: 5812081
- slow: 5640739
- medium: 5455779
- fast: 5164506
- faster: 5099833
- veryfast: 5108824 (file size starts going up from this point)
My question is: This is rather the opposite from what I'd expect. Am I missing something obvious?
ffmpeg h.265
asked Nov 26 '18 at 20:58
ChristopheChristophe
1,36411524
You have to look at both the quality and the bitrate in order to explain what is happening. More bits genrally means higher quality as well (but not always, video is a complex matter )See e.g. stackoverflow.com/questions/14306205/…
– Fredrik Pihl
Dec 5 '18 at 11:38
@FredrikPihl the preset changes the encoding speed to compression ratio, thus better quality and bit-rate here does not result int better picture quality (it results in better compression). Christophe you are right, I think your file is too small, thus there is not a big difference between the presets.
– GramThanos
Jan 26 at 14:34
add a comment |
I'm using ffmpeg on the command line to encode video from a QuickTime ProRes 4444p DCI-resolution source to h.265, y420p. It's working just fine, but I noticed something very odd: If I change nothing but the preset, the file size goes down as the encoding speed goes up:
Preset and resulting file size:
- veryslow: 5814379
- slower: 5812081
- slow: 5640739
- medium: 5455779
- fast: 5164506
- faster: 5099833
- veryfast: 5108824 (file size starts going up from this point)
My question is: This is rather the opposite from what I'd expect. Am I missing something obvious?
ffmpeg h.265
asked Nov 26 '18 at 20:58
ChristopheChristophe
1,36411524
I'm using ffmpeg on the command line to encode video from a QuickTime ProRes 4444p DCI-resolution source to h.265, y420p. It's working just fine, but I noticed something very odd: If I change nothing but the preset, the file size goes down as the encoding speed goes up:
Preset and resulting file size:
- veryslow: 5814379
- slower: 5812081
- slow: 5640739
- medium: 5455779
- fast: 5164506
- faster: 5099833
- veryfast: 5108824 (file size starts going up from this point)
My question is: This is rather the opposite from what I'd expect. Am I missing something obvious?
ffmpeg h.265
ffmpeg h.265
asked Nov 26 '18 at 20:58
ChristopheChristophe
1,36411524
asked Nov 26 '18 at 20:58
ChristopheChristophe
1,36411524
asked Nov 26 '18 at 20:58
ChristopheChristophe
1,36411524
asked Nov 26 '18 at 20:58
ChristopheChristophe
1,36411524
asked Nov 26 '18 at 20:58
ChristopheChristophe
1,36411524
1,36411524
You have to look at both the quality and the bitrate in order to explain what is happening. More bits genrally means higher quality as well (but not always, video is a complex matter )See e.g. stackoverflow.com/questions/14306205/…
– Fredrik Pihl
Dec 5 '18 at 11:38
@FredrikPihl the preset changes the encoding speed to compression ratio, thus better quality and bit-rate here does not result int better picture quality (it results in better compression). Christophe you are right, I think your file is too small, thus there is not a big difference between the presets.
– GramThanos
Jan 26 at 14:34
add a comment |
You have to look at both the quality and the bitrate in order to explain what is happening. More bits genrally means higher quality as well (but not always, video is a complex matter )See e.g. stackoverflow.com/questions/14306205/…
– Fredrik Pihl
Dec 5 '18 at 11:38
@FredrikPihl the preset changes the encoding speed to compression ratio, thus better quality and bit-rate here does not result int better picture quality (it results in better compression). Christophe you are right, I think your file is too small, thus there is not a big difference between the presets.
– GramThanos
Jan 26 at 14:34
You have to look at both the quality and the bitrate in order to explain what is happening. More bits genrally means higher quality as well (but not always, video is a complex matter )See e.g. stackoverflow.com/questions/14306205/…
– Fredrik Pihl
Dec 5 '18 at 11:38
You have to look at both the quality and the bitrate in order to explain what is happening. More bits genrally means higher quality as well (but not always, video is a complex matter )See e.g. stackoverflow.com/questions/14306205/…
– Fredrik Pihl
Dec 5 '18 at 11:38
@FredrikPihl the preset changes the encoding speed to compression ratio, thus better quality and bit-rate here does not result int better picture quality (it results in better compression). Christophe you are right, I think your file is too small, thus there is not a big difference between the presets.
– GramThanos
Jan 26 at 14:34
@FredrikPihl the preset changes the encoding speed to compression ratio, thus better quality and bit-rate here does not result int better picture quality (it results in better compression). Christophe you are right, I think your file is too small, thus there is not a big difference between the presets.
– GramThanos
Jan 26 at 14:34
add a comment |
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You have to look at both the quality and the bitrate in order to explain what is happening. More bits genrally means higher quality as well (but not always, video is a complex matter )See e.g. stackoverflow.com/questions/14306205/…
– Fredrik Pihl
Dec 5 '18 at 11:38
@FredrikPihl the preset changes the encoding speed to compression ratio, thus better quality and bit-rate here does not result int better picture quality (it results in better compression). Christophe you are right, I think your file is too small, thus there is not a big difference between the presets.
– GramThanos
Jan 26 at 14:34