1. 08 Mar, 2016 1 commit
  2. 06 Mar, 2016 1 commit
  3. 02 Mar, 2016 1 commit
    • Ganesh Ajjanagadde's avatar
      lavc/aacenc_utils: replace sqrtf(Q*sqrtf(Q)) by precomputed value · bd9c5875
      Ganesh Ajjanagadde authored
      It makes no sense whatsoever to do this at each function call; we
      already have a table for this.
      
      Yields a 2x improvement in find_min_book (x86-64, Haswell+GCC):
      ffmpeg -i sin.flac -acodec aac -y sin.aac
      find_min_book
      old
          605 decicycles in find_min_book, 8388453 runs,    155 skips.9x
          606 decicycles in find_min_book,16776912 runs,    304 skips.9x
          607 decicycles in find_min_book,33553819 runs,    613 skips.2x
          607 decicycles in find_min_book,67107668 runs,   1196 skips.3x
          607 decicycles in find_min_book,134215360 runs,   2368 skips3x
      
      new
          359 decicycles in find_min_book, 8388552 runs,     56 skips.3x
          360 decicycles in find_min_book,16777112 runs,    104 skips.1x
          361 decicycles in find_min_book,33554218 runs,    214 skips.4x
          361 decicycles in find_min_book,67108381 runs,    483 skips.5x
          361 decicycles in find_min_book,134216725 runs,   1003 skips5x
      
      and more importantly a non-negligible speedup (~ 8%) to overall AAC encoding:
      old:
      ffmpeg -i sin.flac -acodec aac -strict -2 -y sin_new.aac  6.82s user 0.03s system 104% cpu 6.565 total
      new:
      ffmpeg -i sin.flac -acodec aac -strict -2 -y sin_old.aac  6.24s user 0.03s system 104% cpu 5.993 total
      
      This also improves accuracy of the expression by ~ 2 ulp in some cases.
      Reviewed-by: 's avatarDerek Buitenhuis <derek.buitenhuis@gmail.com>
      Reviewed-by: 's avatarRostislav Pehlivanov <atomnuker@gmail.com>
      Signed-off-by: 's avatarGanesh Ajjanagadde <gajjanag@gmail.com>
      bd9c5875
  4. 14 Jan, 2016 1 commit
  5. 14 Dec, 2015 1 commit
  6. 02 Dec, 2015 1 commit
    • Claudio Freire's avatar
      AAC encoder: improve SF range utilization · ca203e99
      Claudio Freire authored
      This patch does 4 things, all of which interact and thus it
      woudln't be possible to commit them separately without causing
      either quality regressions or assertion failures.
      
      Fate comparison targets don't all reflect improvements in
      quality, yet listening tests show substantially improved quality
      and stability.
      
      1. Increase SF range utilization.
      
      The spec requires SF delta values to be constrained within the
      range -60..60. The previous code was applying that range to
      the whole SF array and not only the deltas of consecutive values,
      because doing so requires smarter code: zeroing or otherwise
      skipping a band may invalidate lots of SF choices.
      
      This patch implements that logic to allow the coders to utilize
      the full dynamic range of scalefactors, increasing quality quite
      considerably, and fixing delta-SF-related assertion failures,
      since now the limitation is enforced rather than asserted.
      
      2. PNS tweaks
      
      The previous modification makes big improvements in twoloop's
      efficiency, and every time that happens PNS logic needs to be
      tweaked accordingly to avoid it from stepping all over twoloop's
      decisions. This patch includes modifications of the sort.
      
      3. Account for lowpass cutoff during PSY analysis
      
      The closer PSY's allocation is to final allocation the better
      the quality is, and given these modifications, twoloop is now
      very efficient at avoiding holes. Thus, to compute accurate
      thresholds, PSY needs to account for the lowpass applied
      implicitly during twoloop (by zeroing high bands).
      
      This patch makes twoloop set the cutoff in psymodel's context
      the first time it runs, and makes PSY account for it during
      threshold computation, making PE and threshold computations
      closer to the final allocation and thus achieving better
      subjective quality.
      
      4. Tweaks to RC lambda tracking loop in relation to PNS
      
      Without this tweak some corner cases cause quality regressions.
      Basically, lambda needs to react faster to overall bitrate
      efficiency changes since now PNS can be quite successful in
      enforcing maximum bitrates, when PSY allocates too many bits
      to the lower bands, suppressing the signals RC logic uses to
      lower lambda in those cases and causing aggressive PNS.
      
      This tweak makes PNS much less aggressive, though it can still
      use some further tweaks.
      
      Also update MIPS specializations and adjust fuzz
      
      Also in lavc/mips/aacpsy_mips.h: remove trailing whitespace
      ca203e99
  7. 28 Nov, 2015 1 commit
  8. 17 Oct, 2015 1 commit
  9. 12 Oct, 2015 3 commits
    • Rostislav Pehlivanov's avatar
    • Rostislav Pehlivanov's avatar
      aacenc: add support for changing options based on a profile · 0f4334df
      Rostislav Pehlivanov authored
      This commit adds the ability for a profile to set the default
      options, as well as for the user to override such options
      by simply stating them in the command line while still keeping
      the same profile, as long as those options are still permitted by
      the profile.
      
      Example: setting the profile to aac_low (the default) will turn
      PNS and IS on. They can be disabled by -aac_pns 0 and -aac_is 0,
      respectively. Turning on -aac_pred 1 will cause the profile to be
      elevated to aac_main, as long as no options forbidding aac_main
      have been entered (like AAC-LTP, which will be pushed soon).
      
      A useful feature is that by setting the profile to mpeg2_aac_low,
      all MPEG4 features will be disabled and if the user tries to enable
      them then the program will exit with an error. This profile is
      signalled with the same bitstream as aac_low (MPEG4) but some devices
      and decoders will fail if any MPEG4 features have been enabled.
      0f4334df
    • Rostislav Pehlivanov's avatar
      aacenc_utils: add 'inline' flag to find_form_factor, silence warning · 5f760da6
      Rostislav Pehlivanov authored
      Seems it was forgotten.
      5f760da6
  10. 11 Oct, 2015 1 commit
    • Claudio Freire's avatar
      AAC encoder: Extensive improvements · 01ecb717
      Claudio Freire authored
      This finalizes merging of the work in the patches in ticket #2686.
      
      Improvements to twoloop and RC logic are extensive.
      
      The non-exhaustive list of twoloop improvments includes:
       - Tweaks to distortion limits on the RD optimization phase of twoloop
       - Deeper search in twoloop
       - PNS information marking to let twoloop decide when to use it
         (turned out having the decision made separately wasn't working)
       - Tonal band detection and priorization
       - Better band energy conservation rules
       - Strict hole avoidance
      
      For rate control:
       - Use psymodel's bit allocation to allow proper use of the bit
         reservoir. Don't work against the bit reservoir by moving lambda
         in the opposite direction when psymodel decides to allocate more/less
         bits to a frame.
       - Retry the encode if the effective rate lies outside a reasonable
         margin of psymodel's allocation or the selected ABR.
       - Log average lambda at the end. Useful info for everyone, but especially
         for tuning of the various encoder constants that relate to lambda
         feedback.
      
      Psy:
       - Do not apply lowpass with a FIR filter, instead just let the coder
         zero bands above the cutoff. The FIR filter induces group delay,
         and while zeroing bands causes ripple, it's lost in the quantization
         noise.
       - Experimental VBR bit allocation code
       - Tweak automatic lowpass filter threshold to maximize audio bandwidth
         at all bitrates while still providing acceptable, stable quality.
      
      I/S:
       - Phase decision fixes. Unrelated to #2686, but the bugs only surfaced
         when the merge was finalized. Measure I/S band energy accounting for
         phase, and prevent I/S and M/S from being applied both.
      
      PNS:
       - Avoid marking short bands with PNS when they're part of a window
         group in which there's a large variation of energy from one window
         to the next. PNS can't preserve those and the effect is extremely
         noticeable.
      
      M/S:
       - Implement BMLD protection similar to the specified in
         ISO-IEC/13818:7-2003, Appendix C Section 6.1. Since M/S decision
         doesn't conform to section 6.1, a different method had to be
         implemented, but should provide equivalent protection.
       - Move the decision logic closer to the method specified in
         ISO-IEC/13818:7-2003, Appendix C Section 6.1. Specifically,
         make sure M/S needs less bits than dual stereo.
       - Don't apply M/S in bands that are using I/S
      
      Now, this of course needed adjustments in the compare targets and
      fuzz factors of the AAC encoder's fate tests, but if wondering why
      the targets go up (more distortion), consider the previous coder
      was using too many bits on LF content (far more than required by
      psy), and thus those signals will now be more distorted, not less.
      
      The extra distortion isn't audible though, I carried extensive
      ABX testing to make sure.
      
      A very similar patch was also extensively tested by Kamendo2 in
      the context of #2686.
      01ecb717
  11. 23 Sep, 2015 1 commit
  12. 06 Sep, 2015 1 commit
  13. 11 Aug, 2015 1 commit
    • Rostislav Pehlivanov's avatar
      aacenc: Move small misc. functions to a separate file · ef8e5a61
      Rostislav Pehlivanov authored
      As well as tables littered everywhere, functions were spread
      out all across the encoder's files. This moves them to a single
      place where they can be used by either the encoder's main files
      or additional encoder files. Additionally, it changes the type
      of some to 'inline' to enable us to simply put them in a header
      file and possibly gain some speed due to compiler optimizations.
      Signed-off-by: 's avatarClaudio Freire <klaussfreire@gmail.com>
      ef8e5a61