r8469: x264 encodes under ridiculously large bitrate--resolved

[Spellbinder]

Original: http://rapidshare.com/files/3287447012/original_short.mp4
Encode: http://rapidshare.com/files/3639512902/test_x264_short.mp4

[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