J'utilise ffmpeg pour transcoder un fichier FLV qui n'a qu'un seul groupe d'images, c'est-à-dire que seule la première image est une image I. Le problème est que mon fichier de sortie contient plusieurs images I, mais que j'en ai besoin au début.
Le but est de changer le débit.
J'utilise cette commande pour convertir:
ffmpeg -y -copyts -i 1.flv -acodec copy -vcodec libx264 -r 30 -b:v 500k -g 500 -keyint_min 500 1_500k.flv
La sortie de FFmpeg:
ffmpeg version 1.2 Copyright (c) 2000-2013 the FFmpeg developers
built on May 3 2013 10:11:18 with gcc 4.1.2 (GCC) 20080704 (Red Hat 4.1.2-48)
configuration: --prefix=/usr/local/lib --enable-gpl --enable-nonfree --enable-postproc --enable-pthreads --enable-x11grab --enable-swscale --enable-version3 --disable-ffplay --disable-ffserver --enable-filter=movie --enable-frei0r --enable-libfaac --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-libopencore-amrnb --enable-libopencore-amrwb --extra-cflags='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic -fPIC' --extra-ldflags=-ldl --enable-shared --enable-libopenjpeg --enable-encoder=png --enable-encoder=bmp --enable-encoder=wmv1 --enable-encoder=wmv2
libavutil 52. 18.100 / 52. 18.100
libavcodec 54. 92.100 / 54. 92.100
libavformat 54. 63.104 / 54. 63.104
libavdevice 54. 3.103 / 54. 3.103
libavfilter 3. 42.103 / 3. 42.103
libswscale 2. 2.100 / 2. 2.100
libswresample 0. 17.102 / 0. 17.102
libpostproc 52. 2.100 / 52. 2.100
Input #0, flv, from '1.flv':
Duration: 00:00:03.86, start: 1.000000, bitrate: 195 kb/s
Stream #0:0: Video: vp6f, yuv420p, 320x240, 30 tbr, 1k tbn, 1k tbc
Stream #0:1: Audio: mp3, 22050 Hz, mono, s16p, 48 kb/s
[libx264 @ 0xbffcc0] using cpu capabilities: MMX2 SSE2Fast FastShuffle SSEMisalign LZCNT
[libx264 @ 0xbffcc0] profile High, level 2.0
[libx264 @ 0xbffcc0] 264 - core 118 r0+7M 0176d43 - H.264/MPEG-4 AVC codec - Copyleft 2003-2011 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=500 keyint_min=251 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=abr mbtree=1 bitrate=500 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, flv, to '1_500k.flv':
Metadata:
encoder : Lavf54.63.104
Stream #0:0: Video: h264 ([7][0][0][0] / 0x0007), yuv420p, 320x240, q=-1--1, 500 kb/s, 1k tbn, 30 tbc
Stream #0:1: Audio: mp3 ([2][0][0][0] / 0x0002), 22050 Hz, mono, 48 kb/s
Stream mapping:
Stream #0:0 -> #0:0 (vp6f -> libx264)
Stream #0:1 -> #0:1 (copy)
Press [q] to stop, [?] for help
frame= 75 fps=0.0 q=18.0 Lsize= 148kB time=00:00:03.88 bitrate= 311.7kbits/s
video:127kB audio:17kB subtitle:0 global headers:0kB muxing overhead 2.455463%
[libx264 @ 0xbffcc0] frame I:1 Avg QP:19.31 size: 14022
[libx264 @ 0xbffcc0] frame P:53 Avg QP:13.74 size: 1965
[libx264 @ 0xbffcc0] frame B:21 Avg QP:21.83 size: 551
[libx264 @ 0xbffcc0] consecutive B-frames: 62.7% 0.0% 0.0% 37.3%
[libx264 @ 0xbffcc0] mb I I16..4: 2.7% 64.0% 33.3%
[libx264 @ 0xbffcc0] mb P I16..4: 0.1% 0.2% 0.0% P16..4: 40.3% 5.5% 10.6% 0.0% 0.0% skip:43.4%
[libx264 @ 0xbffcc0] mb B I16..4: 0.1% 0.1% 0.0% B16..8: 30.6% 3.5% 2.5% direct: 2.8% skip:60.4% L0:43.8% L1:49.3% BI: 6.9%
[libx264 @ 0xbffcc0] final ratefactor: 14.33
[libx264 @ 0xbffcc0] 8x8 transform intra:64.8% inter:86.4%
[libx264 @ 0xbffcc0] coded y,uvDC,uvAC intra: 87.5% 96.0% 75.6% inter: 22.7% 21.9% 9.5%
[libx264 @ 0xbffcc0] i16 v,h,dc,p: 29% 19% 48% 5%
[libx264 @ 0xbffcc0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 9% 22% 34% 6% 4% 4% 8% 5% 9%
[libx264 @ 0xbffcc0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 23% 20% 13% 7% 6% 5% 9% 6% 10%
[libx264 @ 0xbffcc0] i8c dc,h,v,p: 59% 19% 16% 6%
[libx264 @ 0xbffcc0] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 0xbffcc0] ref P L0: 79.2% 7.6% 8.3% 4.9%
[libx264 @ 0xbffcc0] ref B L0: 91.0% 6.4% 2.6%
[libx264 @ 0xbffcc0] ref B L1: 93.3% 6.7%
[libx264 @ 0xbffcc0] kb/s:362.09