我有一个充满图像的目录，我正在使用 ffmpeg 将其转换为视频。
第一帧是黑色标题帧，淡入/变形为第一个视频帧，并有 5 帧变形。
我在视频结尾处做了镜像，使用 5 帧变形将最后一个视频帧再次变形为 100％ 白色帧。
我可以查看框架（png 文件），它们是正确的。
但是当我生成视频时，淡入效果看起来不错，但最后它突然从视频帧切换到白色，没有淡入淡出。这是压缩问题吗？还是其他原因？
这是我使用的命令..
ffmpeg -pattern_type glob -i "*.png" -pix_fmt yuv420p -vcodec libx264 -movflags faststart /tmp/out.mp4
以下是 ffmpeg 的输出：
ffmpeg version 2.2.git Copyright (c) 2000-2014 the FFmpeg developers
built on Mar 18 2014 12:58:38 with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5)
configuration: --prefix=/lib/ffmpeg --extra-cflags=-I/lib/ffmpeg/include --extra-ldflags=-L/lib/ffmpeg/lib --bindir=/usr/local/bin --extra-libs=-ldl --enable-gpl --enable-libtheora --enable-libvorbis --enable-libx264 --enable-nonfree
libavutil 52. 67.100 / 52. 67.100
libavcodec 55. 52.102 / 55. 52.102
libavformat 55. 34.101 / 55. 34.101
libavdevice 55. 11.100 / 55. 11.100
libavfilter 4. 3.100 / 4. 3.100
libswscale 2. 5.101 / 2. 5.101
libswresample 0. 18.100 / 0. 18.100
libpostproc 52. 3.100 / 52. 3.100
Input #0, mpeg, from 'pipe:':
Duration: N/A, start: 0.533367, bitrate: 104857 kb/s
Stream #0:0[0x1e0]: Video: mpeg1video, yuv420p(tv), 720x480 [SAR 1:1 DAR 3:2], 104857 kb/s, 29.17 fps, 25 tbr, 90k tbn, 25 tbc
[libx264 @ 0x21af120] using SAR=1/1
[libx264 @ 0x21af120] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 LZCNT
[libx264 @ 0x21af120] profile High, level 3.0
[libx264 @ 0x21af120] 264 - core 142 - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 - 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=24 lookahead_threads=3 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=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to '/tmp/3113866936.9fXLvm/3113866936.mp4':
Metadata:
encoder : Lavf55.34.101
Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 720x480 [SAR 1:1 DAR 3:2], q=-1--1, 12800 tbn, 25 tbc
Stream mapping:
Stream #0:0 -> #0:0 (mpeg1video -> libx264)
[mp4 @ 0x21adfa0] Starting second pass: moving the moov atom to the beginning of the filerop=39
frame= 1045 fps=253 q=-1.0 Lsize= 1678kB time=00:00:41.72 bitrate= 329.6kbits/s dup=1 drop=41
video:1666kB audio:0kB subtitle:0 data:0 global headers:0kB muxing overhead 0.734772%
[libx264 @ 0x21af120] frame I:6 Avg QP:13.20 size: 28432
[libx264 @ 0x21af120] frame P:359 Avg QP:19.17 size: 4154
[libx264 @ 0x21af120] frame B:680 Avg QP:13.98 size: 64
[libx264 @ 0x21af120] consecutive B-frames: 12.5% 1.3% 2.3% 83.8%
[libx264 @ 0x21af120] mb I I16..4: 56.3% 34.5% 9.2%
[libx264 @ 0x21af120] mb P I16..4: 2.6% 4.4% 0.7% P16..4: 11.3% 2.4% 1.5% 0.0% 0.0% skip:77.2%
[libx264 @ 0x21af120] mb B I16..4: 0.5% 0.0% 0.0% B16..8: 2.3% 0.1% 0.0% direct: 0.2% skip:96.9% L0:26.2% L1:71.8% BI: 1.9%
[libx264 @ 0x21af120] 8x8 transform intra:48.6% inter:82.7%
[libx264 @ 0x21af120] coded y,uvDC,uvAC intra: 47.1% 49.5% 21.3% inter: 3.2% 3.9% 0.8%
[libx264 @ 0x21af120] i16 v,h,dc,p: 74% 15% 7% 4%
[libx264 @ 0x21af120] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 26% 25% 22% 3% 4% 3% 6% 4% 7%
[libx264 @ 0x21af120] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 37% 27% 12% 3% 4% 4% 6% 3% 5%
[libx264 @ 0x21af120] i8c dc,h,v,p: 55% 22% 19% 5%
[libx264 @ 0x21af120] Weighted P-Frames: Y:20.3% UV:20.1%
[libx264 @ 0x21af120] ref P L0: 59.8% 17.6% 19.7% 2.7% 0.2%
[libx264 @ 0x21af120] ref B L0: 66.1% 29.0% 4.9%
[libx264 @ 0x21af120] ref B L1: 94.4% 5.6%
[libx264 @ 0x21af120] kb/s:326.42