Changes between Initial Version and Version 1 of Ticket #2173, comment 2


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Timestamp:
03/05/2013 11:20:12 AM (3 months ago)
Author:
bonconboy
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  • Ticket #2173, comment 2

    initial v1  
    1414}}} 
    1515"bluray-compat" of x264 option forces the number of bframe, bpyramid(=normal or strict), weightp(0 or 1), aud=1、and nal-hrd=vbr. Of course, even when using "vbv-maxrate=12000:vbv-bufsize=12000:bluray-compat", the above problem appears. 
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    17  
     16  
    1817> Or in other words: If it works fine without, why do you believe there is a bug? 
    1918When using "vbv-maxrate=12000:vbv-bufsize=12000:nal-hrd=vbr" with handbrake to make mkv or mp4 for converting to AVCHD, no problem. 
    2019And I understand nal is addressed in libavformat/avc.c in ffmpeg. 
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    2221> And if you can answer the two questions: 
    2322> Do any of the following (untested) x264 options make a difference (does it work for some but not for others)? 
    2423> "vbv-maxrate=12000:vbv-bufsize=12000" 
    2524No problem. x264 addresses vbv-maxrate and vbv-bufsize, independent of nal, though both are the parameter of nal. 
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    2726> "vbv-maxrate=12000:nal-hrd=vbr" 
    2827> "vbv-bufsize=12000:nal-hrd=vbr" 
    2928x264 ignore these because nal needs vbv-maxrate and vbv-bufsize. 
    3029If you need files and console, I will upload them. 
    31  
    32 But I cannot identify a cause and if nal is a cause for the above. 
    33 Now what I can do is to report facts. 
    34  
    35 my understanding nal. If wrong, please pointing out. 
    36 Nal unit consists of VCL(Video Coding Layer) and non-VCL.  
    37 VCL-NAL unit is slice data. 
    38 Non-VCL-NAL units are  
    39 SEI(Supplemental Enhancement Information) 
    40 SPS(Sequence Parameter Set) 
    41 PPS(Picture Parameter Set) 
    42 AUD(Access Unit Delimiter) 
    43 Filler data（since x264 r1480, when using --nal-hrd=cbr) 
    44  
    45 SEI-NAL can includes some SEI messages 
    46 Buffering period 
    47 Picture timing 
    48 User data registered by ITU-T Recommendation T.35 
    49 User data unregistered（the enode settings in x264） 
    50 Recovery point（including broken_link_flag） 
    51 and so on. omit them because x264 don't use them 
    52  
    53 SPS is basic information of decoding stream 
    54 profile_idc 
    55 level_idc 
    56 num_ref_frames 
    57 pic_width_in_mbs_minus1 
    58 pic_height_in_map_units_minus1 
    59 frame_mbs_only_flag 
    60 mb_adaptive_frame_field_flag(MBAFF) 
    61 direct_8x8_inference_flag 
    62 frame_cropping_flag 
    63 VUI(Video Usability Information) 
    64 and so on. omit them 
    65  
    66 PPS is necessary information for decoing each picture(frame) 
    67 entropy_coding_mode_flag(CAVLC/CABAC) 
    68 weighted_pred_flag(weightp) 
    69 weighted_bipred_flag(weightb) 
    70 pic_init_qp_minus26(QP) 
    71 chroma_qp_index_offset 
    72 deblocking_filter_control_present_flag 
    73 constrained_intra_pred_flag 
    74 slice and picture corresponding infomation 
    75 and so on. omit them 
    76  
    77 AUD(Access Unit Delimiter) 
    78  
    79 The order of NAL unit is important, eg、AUD, SPS, PPS, SEI…..