LAME -q switch: Difference between revisions

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=VBR=
=Internal Variables=


{| border=1 class="wikitable" style="text-align:center"
{| border=1 class="wikitable" style="text-align:center"
! -q n !! huffman search !! sv_qnt.substep_shaping !! subblock gain !! noise shaping !! amplification !! stopping
! -q n !! huffman search !! full_outer_loop !! sv_qnt.substep_shaping !! subblock gain !! noise shaping !! amplification !! stopping !! description
|-
|-
| 0
| 0 || best  || 1 || 2 ||  1 || 1 || 2 || 1 || align="left" | Use slowest & best possible version of all algorithms.
|-
|-
| 1
| 1 || best  || 0 || 2 ||  1 || 1 || 2 || 1 ||
|-
|-
| 2
| 2 || best  || 0 || 2 ||  1 || 1 || 1 || 1 || align="left" | Recommended.  Same as -h.  -q 0 and -q 1 are slow and may not produce significantly higher quality.
|-
|-
| 3
| 3 || best  || 0 || ? ||  1 || 1 || 1 || 1 || align="left" | Default value. Good speed, good quality.
|-
|-
| 4
| 4 || best  || 0 || ? ||  1 || 1 || 0 || 0 ||
|-
|-
| 5
| 5-6 || normal || 0 || ? ||  1 || 1 || 0 || 0 ||
|-
|-
| 6
| 7-8 || normal || 0 || ? || -1 || 0 || 0 || 0 || align="left" | Same as -f. Very fast, ok quality. (psycho acoustics are used for pre-echo & M/S, but no noise shaping is done.
|-
|-
| 7
| 9 || normal || 0 || ? || -1 || 0 || 0 || 0 || align="left" | Disables almost all algorithms including psy-model. Poor quality.
|}
 
= VBR =
 
{| border=1 class="wikitable"
! -q n !! description
|-
|-
| 8
| 0-4 || Default value. Use the best algorithm.
|-
|-
| 9
| 5-6 || Use the not so good algorithm
|-
| 7-9 ||
|}
|}


 
=Observations=
=CBR / ABR=
* -q 5-6 Output Same Results. LAME header will indicate the different quality parameter. But the files are otherwise a perfect match.
* -q 7-8 Is always mapped to -q 7 and thus outputs identical files, including the LAME header.
* -q 9 Output is same as -q 7. But official doc describes it as a different quality. LAME header will be different for CBR/ABR and identical for VBR.

Revision as of 13:56, 3 June 2013

Internal Variables

-q n huffman search full_outer_loop sv_qnt.substep_shaping subblock gain noise shaping amplification stopping description
0 best 1 2 1 1 2 1 Use slowest & best possible version of all algorithms.
1 best 0 2 1 1 2 1
2 best 0 2 1 1 1 1 Recommended. Same as -h. -q 0 and -q 1 are slow and may not produce significantly higher quality.
3 best 0 ? 1 1 1 1 Default value. Good speed, good quality.
4 best 0 ? 1 1 0 0
5-6 normal 0 ? 1 1 0 0
7-8 normal 0 ? -1 0 0 0 Same as -f. Very fast, ok quality. (psycho acoustics are used for pre-echo & M/S, but no noise shaping is done.
9 normal 0 ? -1 0 0 0 Disables almost all algorithms including psy-model. Poor quality.

VBR

-q n description
0-4 Default value. Use the best algorithm.
5-6 Use the not so good algorithm
7-9

Observations

  • -q 5-6 Output Same Results. LAME header will indicate the different quality parameter. But the files are otherwise a perfect match.
  • -q 7-8 Is always mapped to -q 7 and thus outputs identical files, including the LAME header.
  • -q 9 Output is same as -q 7. But official doc describes it as a different quality. LAME header will be different for CBR/ABR and identical for VBR.