I am using this command to transcode my videos in ffmpeg: ffmpeg -i 1_med.mp4 -movflags faststart -c:v libx264 -x264opts 'keyint=100:min-keyint=25:no-scenecut:8x8dct:sliced-threads=0' -deblock 1:1 -flags +loop -b:v 850k -maxrate 850k -bufsize 2000k -vf "scale=-1280:720:flags=spline+full_chroma_inp+full_chroma_int+accurate_rnd+bitexact" -acodec libfdk_aac -b:a 320k -coder 1 -me_range 16 -bf 10 -q:v 1 -qmin 0 -qmax 69 -trellis 2 -mbtree 1 -mixed-refs 1 -preset veryfast medfull.mp4
and here is the output of mediainfo: Complete name : medToCheck.mp4 Format : MPEG-4 Format profile : Base Media Codec ID : isom File size : 79.0 MiB Duration : 10mn 0s Overall bit rate mode : Variable Overall bit rate : 1 104 Kbps Writing application : Lavf56.25.101 Video ID : 1 Format : AVC Format/Info : Advanced Video Codec Format profile : [email protected] Format settings, CABAC : Yes Format settings, ReFrames : 4 frames Codec ID : avc1 Codec ID/Info : Advanced Video Coding Duration : 10mn 0s Bit rate : 779 Kbps Nominal bit rate : 850 Kbps Width : 1 280 pixels Height : 720 pixels Display aspect ratio : 16:9 Frame rate mode : Constant Frame rate : 25.000 fps Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.034 Stream size : 55.7 MiB (71%) Writing library : x264 core 142 r2495 6a301b6 Encoding settings : cabac=1 / ref=1 / deblock=1:1:1 / analyse=0x3:0x113 / me=hex / subme=2 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=0 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=0 / threads=4 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=10 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=1 / keyint=100 / keyint_min=25 / scenecut=0 / intra_refresh=0 / rc_lookahead=10 / rc=cbr / mbtree=1 / bitrate=850 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / vbv_maxrate=850 / vbv_bufsize=2000 / nal_hrd=none / filler=0 / ip_ratio=1.40 / aq=1:1.00 Language : English Audio ID : 2 Format : AAC Format/Info : Advanced Audio Codec Format profile : LC Codec ID : 40 Duration : 10mn 0s Bit rate mode : Variable Bit rate : 320 Kbps Maximum bit rate : 850 Kbps Channel count : 2 channels Channel positions : Front: L R Sampling rate : 48.0 KHz Compression mode : Lossy Delay relative to video : 80ms Stream size : 22.9 MiB (29%) Language : English and ffmpeg console output: [root@vm1-108 FullVideoToTestOurCommand2]# ffmpeg -i 1_med.mp4 -movflags faststart -c:v libx264 -x264opts 'keyint=100:min-keyint=25:no-scenecut:8x8dct:sliced-threads=0' -deblock 1:1 -flags +loop -b:v 850k -maxrate 850k -bufsize 2000k -vf "scale=-1280:720:flags=spline+full_chroma_inp+full_chroma_int+accurate_rnd+bitexact" -acodec libfdk_aac -b:a 320k -coder 1 -me_range 16 -bf 10 -q:v 1 -qmin 0 -qmax 69 -trellis 2 -mbtree 1 -mixed-refs 1 -preset veryfast -ss 00:00:00 -t 00:10:00 medToCheckNominalBitrateWithBufzieEqualToMaxrate.mp4 ffmpeg version 2.6.8 Copyright (c) 2000-2016 the FFmpeg developers built with gcc 4.8.5 (GCC) 20150623 (Red Hat 4.8.5-4) configuration: --prefix=/usr --bindir=/usr/bin --datadir=/usr/share/ffmpeg --incdir=/usr/include/ffmpeg --libdir=/usr/lib64 --mandir=/usr/share/man --arch=x86_64 --optflags='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic' --enable-bzlib --disable-crystalhd --enable-gnutls --enable-ladspa --enable-libass --enable-libcdio --enable-libdc1394 --enable-libfaac --enable-nonfree --enable-libfdk-aac --enable-nonfree --disable-indev=jack --enable-libfreetype --enable-libgsm --enable-libmp3lame --enable-openal --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libv4l2 --enable-libx264 --enable-libx265 --enable-libxvid --enable-x11grab --enable-avfilter --enable-avresample --enable-postproc --enable-pthreads --disable-static --enable-shared --enable-gpl --disable-debug --disable-stripping --shlibdir=/usr/lib64 --enable-runtime-cpudetect libavutil 54. 20.100 / 54. 20.100 libavcodec 56. 26.100 / 56. 26.100 libavformat 56. 25.101 / 56. 25.101 libavdevice 56. 4.100 / 56. 4.100 libavfilter 5. 11.102 / 5. 11.102 libavresample 2. 1. 0 / 2. 1. 0 libswscale 3. 1.101 / 3. 1.101 libswresample 1. 1.100 / 1. 1.100 libpostproc 53. 3.100 / 53. 3.100 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '1_med.mp4': Metadata: major_brand : isom minor_version : 512 compatible_brands: isomiso2avc1mp41 encoder : Lavf57.52.100 Duration: 01:08:51.20, start: 0.042667, bitrate: 810 kb/s Stream #0:0(eng): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 741 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default) Metadata: handler_name : VideoHandler Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 64 kb/s (default) Metadata: handler_name : SoundHandler File 'medToCheckNominalBitrateWithBufzieEqualToMaxrate.mp4' already exists. Overwrite ? [y/N] y [libx264 @ 0x1c2cee0] -qscale is ignored, -crf is recommended. [libx264 @ 0x1c2cee0] using SAR=1/1 [libx264 @ 0x1c2cee0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX AVX2 FMA3 BMI2 [libx264 @ 0x1c2cee0] profile High, level 3.1 [libx264 @ 0x1c2cee0] 264 - core 142 r2495 6a301b6 - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 - http://www.videolan.org/x264.html - options: cabac=1 ref=1 deblock=1:1:1 analyse=0x3:0x113 me=hex subme=2 psy=1 psy_rd=1.00:0.00 mixed_ref=0 me_range=16 chroma_me=1 trellis=2 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=0 threads=4 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=10 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=1 keyint=100 keyint_min=25 scenecut=0 intra_refresh=0 rc_lookahead=10 rc=cbr mbtree=1 bitrate=850 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 vbv_maxrate=850 vbv_bufsize=2000 nal_hrd=none filler=0 ip_ratio=1.40 aq=1:1.00 Output #0, mp4, to 'medToCheckNominalBitrateWithBufzieEqualToMaxrate.mp4': Metadata: major_brand : isom minor_version : 512 compatible_brands: isomiso2avc1mp41 encoder : Lavf56.25.101 Stream #0:0(eng): Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], q=0-69, 850 kb/s, 25 fps, 12800 tbn, 25 tbc (default) Metadata: handler_name : VideoHandler encoder : Lavc56.26.100 libx264 Stream #0:1(eng): Audio: aac (libfdk_aac) ([64][0][0][0] / 0x0040), 48000 Hz, stereo, s16, 320 kb/s (default) Metadata: handler_name : SoundHandler encoder : Lavc56.26.100 libfdk_aac Stream mapping: Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264)) Stream #0:1 -> #0:1 (aac (native) -> aac (libfdk_aac)) Press [q] to stop, [?] for help [mp4 @ 0x1c2be00] Starting second pass: moving the moov atom to the beginning of the filerop=0 frame=15000 fps=158 q=-1.0 Lsize= 80894kB time=00:10:00.00 bitrate=1104.5kbits/s dup=1 drop=0 video:57061kB audio:23439kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.489798% [libx264 @ 0x1c2cee0] frame I:150 Avg QP:11.96 size: 68404 [libx264 @ 0x1c2cee0] frame P:3087 Avg QP:17.97 size: 8810 [libx264 @ 0x1c2cee0] frame B:11763 Avg QP:17.67 size: 1783 [libx264 @ 0x1c2cee0] consecutive B-frames: 8.3% 0.9% 0.9% 0.9% 1.6% 28.5% 31.9% 3.4% 2.9% 2.3% 18.3% [libx264 @ 0x1c2cee0] mb I I16..4: 28.7% 29.4% 42.0% [libx264 @ 0x1c2cee0] mb P I16..4: 11.5% 3.8% 0.4% P16..4: 31.8% 7.8% 3.4% 0.0% 0.0% skip:41.4% [libx264 @ 0x1c2cee0] mb B I16..4: 0.4% 0.1% 0.0% B16..8: 7.4% 1.3% 0.1% direct:12.1% skip:78.6% L0:49.2% L1:44.4% BI: 6.4% [libx264 @ 0x1c2cee0] 8x8 transform intra:24.3% inter:26.3% [libx264 @ 0x1c2cee0] coded y,uvDC,uvAC intra: 24.7% 47.8% 14.8% inter: 2.6% 18.2% 0.3% [libx264 @ 0x1c2cee0] i16 v,h,dc,p: 55% 26% 14% 5% [libx264 @ 0x1c2cee0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 28% 31% 32% 2% 1% 1% 2% 1% 2% [libx264 @ 0x1c2cee0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 30% 29% 13% 4% 5% 4% 6% 5% 4% [libx264 @ 0x1c2cee0] i8c dc,h,v,p: 57% 22% 18% 3% [libx264 @ 0x1c2cee0] Weighted P-Frames: Y:8.6% UV:7.4% [libx264 @ 0x1c2cee0] kb/s:779.06 I need the bitrate to be constant and equal to the one specified (-b:v). after transcoding and using mediainfo, I see that there is a bitrate (which is lower that what I specified) and a nominal bitrate that is equal to expected bitrate. how can I fix this issue?? _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
