r8469: x264 encodes under ridiculously large bitrate--resolved

Started by theat934, February 15, 2013, 06:05:16 AM

Previous topic - Next topic

Jan Gruuthuse

Have the same weird variable FPS result with that video clip. Have not come across videos behaving like this? So looks like developer(s) can help with this one.

Spellbinder

And what about the Bitrate. Did you get 1500? Or half that, too. Because I think this is also a Bug.

Jan Gruuthuse

Rather a point of view, I think for the variable bit rate. 718 Kbps (1 500 Kbps)
Bit rate mode                        : Variable
Bit rate                                 : 718 Kbps
Nominal bit rate                    : 1 500 Kbps
The fps is happening to when using mp4 muxer instead of mp4v2 and xvid.
either something with source video or .... anyway is beyond my user knowledge.
I leave this issue for the developer(s)

Spellbinder

Ok, do I have to do something to trigger the developers, or is this thread enough?

Jan Gruuthuse

Best make a new thread for the FPS issue with an exclamation point icon. The large bitrate is probably picked up. We will see how it goes.

ajschult

I was hitting a similar issue (huge files) with x264, using a saved profile.  The issue was that max_qp=0 ("Maximum Quantiser" on the Quantiser tab).  Before r8458,  the "Quantiser Control" widgets were disabled and the profile that got saved had 0 instead of the default (which was 51).  With r8458, the widgets are enabled and effect encoding.  qp_min and qp_step were also saved as 0 (current defaults are 0 and 4; old defaults were 10 and 4), but don't have such a dramatic effect on encoding.

Spellbinder

Setting those parameters did not help. Still same "Halfed-Bitrate" result.

Avidemux 2.6.1 SVN r8473 (32-bit)


#PY  <- Needed to identify #
#--automatically built--

adm = Avidemux()
adm.loadVideo("I:/TEST/test_ORIGINAL.mp4")
adm.clearSegments()
adm.addSegment(0, 0, 147984000)
adm.markerA = 0
adm.markerB = 147984000
adm.videoCodec("x264", "general.params=2PASSBITRATE=1000", "general.threads=99", "general.fast_first_pass=True", "level=4294967295", "vui.sar_height=1", "vui.sar_width=1", "MaxRefFrames=3", "MinIdr=25", "MaxIdr=250", "i_scenecut_threshold=30"
, "intra_refresh=False", "MaxBFrame=16", "i_bframe_adaptive=2", "i_bframe_bias=0", "i_bframe_pyramid=2", "b_deblocking_filter=True", "i_deblocking_filter_alphac0=0", "i_deblocking_filter_beta=0", "cabac=True"
, "interlaced=False", "constrained_intra=False", "tff=True", "fake_interlaced=False", "analyze.b_8x8=True", "analyze.b_i4x4=True", "analyze.b_i8x8=True", "analyze.b_p8x8=False", "analyze.b_p16x16=True"
, "analyze.b_b16x16=True", "analyze.weighted_pred=2", "analyze.weighted_bipred=True", "analyze.direct_mv_pred=3", "analyze.chroma_offset=0", "analyze.me_method=2", "analyze.me_range=16", "analyze.mv_range=32"
, "analyze.mv_range_thread=-1", "analyze.subpel_refine=8", "analyze.chroma_me=True", "analyze.mixed_references=True", "analyze.trellis=2", "analyze.psy_rd=0.000000", "analyze.psy_trellis=0.000000", "analyze.fast_pskip=False"
, "analyze.dct_decimate=True", "analyze.noise_reduction=0", "analyze.psy=True", "analyze.intra_luma=21", "analyze.inter_luma=21", "ratecontrol.rc_method=0", "ratecontrol.qp_constant=0", "ratecontrol.qp_min=0"
, "ratecontrol.qp_max=69", "ratecontrol.qp_step=4", "ratecontrol.bitrate=0", "ratecontrol.rate_tolerance=1.000000", "ratecontrol.vbv_max_bitrate=0", "ratecontrol.vbv_buffer_size=0", "ratecontrol.vbv_buffer_init=0"
, "ratecontrol.ip_factor=1.400000", "ratecontrol.pb_factor=1.300000", "ratecontrol.aq_mode=2", "ratecontrol.aq_strength=1.000000", "ratecontrol.mb_tree=True", "ratecontrol.lookahead=50")
adm.audioClearTracks()
adm.audioAddTrack(0)
adm.audioCodec(0, "copy");
adm.audioSetDrc(0, 0)
adm.audioSetShift(0, 0,0)
adm.setContainer("MP4V2", "optimize=0", "add_itunes_metadata=0")

theat934

I had some time to look into the x264 high bitrate encoding issue again. First thing, I got the latest build to update the software on my Mac (OS 10.7.5); the latest Avidemux3 version I am trying at this point is r8492.

In my tests, the issue persisted until I tried ajschult's tip to regulate the Maximum Quantiser parameter. Dear friends, this did the trick for me. I revisited the 2.5.4 (avidemux2) version I also have installed, and the x264 quantiser parameters have default values as follows:
Minimum Quantiser: 10
Maximum Quantiser: 51
Max Quantiser Step: 4
Simply setting the Maximum Quantiser parameter to a nonzero value resolved the problem for me.

Many thanks again to ajschult, Spellbinder for sharing and his own testing, and Jan for his expert advice--and the tip for the FPS issue, too.

For the record, I am installing the latest Avidemux builds on Mac with Homebrew
http://mxcl.github.com/homebrew
based on nibbles's avidemux3.rb formula and guidelines for --HEAD installation here:
http://www.avidemux.org/smf/index.php?topic=9960.msg53651