它是一个后端API（在Ruby on Rails中开发），iphone和Android手机用于上传视频。 API正在将上传的视频转换为MP4格式。我在后端使用paperclip-ffmpeg gem进行视频转换。这是我使用的：
has_attached_file :video ,
:styles=>{
:medium=>{ :geometry=>"480x360",:format=>'mp4',:streaming => true,
:convert_options => { :output =>
{
:acodec => 'aac',
:ac => 2 ,
:strict => 'experimental',
'b:a' => '160k',
:vcodec => 'libx264',
:preset => 'slow',
'profile:v' => 'baseline',
:level => '30',
:maxrate => '10000000',
:bufsize => '10000000',
'b:v' => '750k',
:f => 'mp4',
:threads => '0'
}
} },
:thumb => { :geometry => "160x120", :format => 'jpg', :time => 2 },
:thumb_large => { :geometry => "520x390", :format => 'jpg', :time => 2}
}, :processors => [:ffmpeg, :qtfaststart],
:path => path/to/store/video,
:url => url/of/video
我面临的问题是：
当用户从Android手机上传视频时，它在Android上运行完美但在iPhone上无法播放。当用户从iPhone上传视频时，会发生更奇怪的事情，然后在视频上传后播放完美，但经过一段时间（2或3小时）后停止播放这些视频。
如何摆脱这两个问题？任何建议将不胜感激。感谢
@Michael，这是android mobile上传的视频转换的详细日志
ffmpeg version git-2013-05-28-ced0307 Copyright (c) 2000-2013 the FFmpeg developers
built on May 28 2013 07:45:18 with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5)
configuration: --extra-libs=-ldl --enable-gpl --enable-libass --enable-libfdk-aac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libopus --enable-libvpx --enable-x11grab --enable-libx264 --enable-nonfree --enable-version3
libavutil 52. 34.100 / 52. 34.100
libavcodec 55. 12.100 / 55. 12.100
libavformat 55. 7.100 / 55. 7.100
libavdevice 55. 1.101 / 55. 1.101
libavfilter 3. 72.100 / 3. 72.100
libswscale 2. 3.100 / 2. 3.100
libswresample 0. 17.102 / 0. 17.102
libpostproc 52. 3.100 / 52. 3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l':
Metadata:
major_brand : isom
minor_version : 0
compatible_brands: isom3gp4
creation_time : 2013-06-19 15:39:02
Duration: 00:00:25.88, start: 0.000000, bitrate: 16700 kb/s
Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080, 16829 kb/s, 29.75 fps, 30 tbr, 90k tbn, 180k tbc
Metadata:
rotate : 90
creation_time : 2013-06-19 15:39:02
handler_name : VideoHandle
Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 122 kb/s
Metadata:
creation_time : 2013-06-19 15:39:02
handler_name : SoundHandle
[libx264 @ 0x2613c00] using cpu capabilities: MMX2 SSE2Fast SSEMisalign LZCNT
[libx264 @ 0x2613c00] profile Constrained Baseline, level 3.0
[libx264 @ 0x2613c00] 264 - core 133 r2 a3ac64b - H.264/MPEG-4 AVC codec - Copyleft 2003-2013 - http://www.videolan.org/x264.html - options: cabac=0 ref=5 deblock=1:0:0 analyse=0x1:0x111 me=umh subme=8 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=3 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=50 rc=abr mbtree=1 bitrate=750 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 vbv_maxrate=10000 vbv_bufsize=10000 nal_hrd=none ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p.mp4':
Metadata:
major_brand : isom
minor_version : 0
compatible_brands: isom3gp4
encoder : Lavf55.7.100
Stream #0:0(eng): Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 640x360, q=-1--1, 750 kb/s, 15360 tbn, 30 tbc
Metadata:
rotate : 90
creation_time : 2013-06-19 15:39:02
handler_name : VideoHandle
Stream #0:1(eng): Audio: aac ([64][0][0][0] / 0x0040), 48000 Hz, stereo, fltp, 160 kb/s
Metadata:
creation_time : 2013-06-19 15:39:02
handler_name : SoundHandle
Stream mapping:
Stream #0:0 -> #0:0 (h264 -> libx264)
Stream #0:1 -> #0:1 (aac -> aac)
Press [q] to stop, [?] for help
frame= 765 fps= 19 q=-1.0 Lsize= 2621kB time=00:00:25.88 bitrate= 829.4kbits/s dup=7 drop=0
video:2093kB audio:504kB subtitle:0 global headers:0kB muxing overhead 0.878228%
[libx264 @ 0x2613c00] frame I:4 Avg QP:25.48 size: 11731
[libx264 @ 0x2613c00] frame P:761 Avg QP:26.71 size: 2754
[libx264 @ 0x2613c00] mb I I16..4: 33.0% 0.0% 67.0%
[libx264 @ 0x2613c00] mb P I16..4: 2.1% 0.0% 0.9% P16..4: 47.2% 9.5% 3.4% 0.0% 0.0% skip:36.9%
[libx264 @ 0x2613c00] final ratefactor: 23.58
[libx264 @ 0x2613c00] coded y,uvDC,uvAC intra: 31.9% 54.5% 9.5% inter: 11.9% 24.4% 0.5%
[libx264 @ 0x2613c00] i16 v,h,dc,p: 25% 33% 7% 34%
[libx264 @ 0x2613c00] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 17% 14% 9% 14% 10% 10% 11% 8% 7%
[libx264 @ 0x2613c00] i8c dc,h,v,p: 50% 25% 17% 9%
[libx264 @ 0x2613c00] ref P L0: 67.6% 15.2% 10.1% 3.9% 3.2%
[libx264 @ 0x2613c00] kb/s:672.30
ffmpeg version git-2013-05-28-ced0307 Copyright (c) 2000-2013 the FFmpeg developers
built on May 28 2013 07:45:18 with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5)
configuration: --extra-libs=-ldl --enable-gpl --enable-libass --enable-libfdk-aac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libopus --enable-libvpx --enable-x11grab --enable-libx264 --enable-nonfree --enable-version3
libavutil 52. 34.100 / 52. 34.100
libavcodec 55. 12.100 / 55. 12.100
libavformat 55. 7.100 / 55. 7.100
libavdevice 55. 1.101 / 55. 1.101
libavfilter 3. 72.100 / 3. 72.100 <Hashie::Mash groups="{\"groups\":[0]}" post="uploaded from android" route_info=version=v1, method=POST, path=/:version/videos/create(.:format) user_id=31 version="v1" video=#<Hashie::Mash filename="video" head="Content-Disposition: form-data; name=\"video\"; filename=\"video\"\r\nContent-Type: application/octet-stream\r\n" name="video" tempfile=#<File:/tmp/RackMultipart20130620-28711-187049m>>
libswscale 2. 3.100 / 2. 3.100
libswresample 0. 17.102 / 0. 17.102
libpostproc 52. 3.100 / 52. 3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi06.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf55.7.100
Duration: 00:00:25.91, start: 0.021333, bitrate: 828 kb/s
Stream #0:0(eng): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 640x360, 672 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc
Metadata:
rotate : 90
handler_name : VideoHandler
Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 159 kb/s
Metadata:
handler_name : SoundHandler
[libx264 @ 0x326d820] using cpu capabilities: MMX2 SSE2Fast SSEMisalign LZCNT
[libx264 @ 0x326d820] profile Constrained Baseline, level 3.0
[libx264 @ 0x326d820] 264 - core 133 r2 a3ac64b - H.264/MPEG-4 AVC codec - Copyleft 2003-2013 - http://www.videolan.org/x264.html - options: cabac=0 ref=5 deblock=1:0:0 analyse=0x1:0x111 me=umh subme=8 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=3 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=50 rc=abr mbtree=1 bitrate=750 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 vbv_maxrate=10000 vbv_bufsize=10000 nal_hrd=none ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi0620130620-28711-130rd1i.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf55.7.100
Stream #0:0(eng): Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 480x270, q=-1--1, 750 kb/s, 15360 tbn, 30 tbc
Metadata:
rotate : 90
handler_name : VideoHandler
Stream #0:1(eng): Audio: aac ([64][0][0][0] / 0x0040), 48000 Hz, stereo, fltp, 160 kb/s
Metadata:
handler_name : SoundHandler
Stream mapping:
Stream #0:0 -> #0:0 (h264 -> libx264)
Stream #0:1 -> #0:1 (aac -> aac)
Press [q] to stop, [?] for help
frame= 766 fps= 38 q=-1.0 Lsize= 2666kB time=00:00:25.90 bitrate= 843.2kbits/s dup=1 drop=0
video:2138kB audio:505kB subtitle:0 global headers:0kB muxing overhead 0.863633%
[libx264 @ 0x326d820] frame I:4 Avg QP:20.82 size: 11283
[libx264 @ 0x326d820] frame P:762 Avg QP:22.03 size: 2813
[libx264 @ 0x326d820] mb I I16..4: 19.9% 0.0% 80.1%
[libx264 @ 0x326d820] mb P I16..4: 1.7% 0.0% 1.1% P16..4: 49.3% 20.6% 7.0% 0.0% 0.0% skip:20.3%
[libx264 @ 0x326d820] final ratefactor: 19.24
[libx264 @ 0x326d820] coded y,uvDC,uvAC intra: 43.4% 76.7% 29.0% inter: 23.0% 44.6% 1.7%
[libx264 @ 0x326d820] i16 v,h,dc,p: 23% 29% 9% 39%
[libx264 @ 0x326d820] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 12% 21% 9% 11% 10% 10% 11% 8% 8%
[libx264 @ 0x326d820] i8c dc,h,v,p: 44% 26% 18% 12%
[libx264 @ 0x326d820] ref P L0: 74.0% 13.1% 7.7% 3.0% 2.1%
[libx264 @ 0x326d820] kb/s:685.81
ffmpeg version git-2013-05-28-ced0307 Copyright (c) 2000-2013 the FFmpeg developers
built on May 28 2013 07:45:18 with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5)
configuration: --extra-libs=-ldl --enable-gpl --enable-libass --enable-libfdk-aac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libopus --enable-libvpx --enable-x11grab --enable-libx264 --enable-nonfree --enable-version3
libavutil 52. 34.100 / 52. 34.100
libavcodec 55. 12.100 / 55. 12.100
libavformat 55. 7.100 / 55. 7.100
libavdevice 55. 1.101 / 55. 1.101
libavfilter 3. 72.100 / 3. 72.100
libswscale 2. 3.100 / 2. 3.100
libswresample 0. 17.102 / 0. 17.102
libpostproc 52. 3.100 / 52. 3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi06.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf55.7.100
Duration: 00:00:25.91, start: 0.021333, bitrate: 828 kb/s
Stream #0:0(eng): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 640x360, 672 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc
Metadata:
rotate : 90
handler_name : VideoHandler
Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 159 kb/s
Metadata:
handler_name : SoundHandler
Output #0, image2, to '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi0620130620-28711-1bdslpu.jpg':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf55.7.100
Stream #0:0(eng): Video: mjpeg, yuvj420p, 160x90, q=2-31, 200 kb/s, 90k tbn, 30 tbc
Metadata:
rotate : 90
handler_name : VideoHandler
Stream mapping:
Stream #0:0 -> #0:0 (h264 -> mjpeg)
Press [q] to stop, [?] for help
frame= 1 fps=0.0 q=0.0 Lsize=N/A time=00:00:00.03 bitrate=N/A dup=0 drop=57
video:4kB audio:0kB subtitle:0 global headers:0kB muxing overhead -100.479303%
ffmpeg version git-2013-05-28-ced0307 Copyright (c) 2000-2013 the FFmpeg developers
built on May 28 2013 07:45:18 with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5)
configuration: --extra-libs=-ldl --enable-gpl --enable-libass --enable-libfdk-aac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libopus --enable-libvpx --enable-x11grab --enable-libx264 --enable-nonfree --enable-version3
libavutil 52. 34.100 / 52. 34.100
libavcodec 55. 12.100 / 55. 12.100
libavformat 55. 7.100 / 55. 7.100
libavdevice 55. 1.101 / 55. 1.101
libavfilter 3. 72.100 / 3. 72.100
libswscale 2. 3.100 / 2. 3.100
libswresample 0. 17.102 / 0. 17.102
libpostproc 52. 3.100 / 52. 3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi06.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf55.7.100
Duration: 00:00:25.91, start: 0.021333, bitrate: 828 kb/s
Stream #0:0(eng): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 640x360, 672 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc
Metadata:
rotate : 90
handler_name : VideoHandler
Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 159 kb/s
Metadata:
handler_name : SoundHandler
Output #0, image2, to '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi0620130620-28711-1vp4al6.jpg':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf55.7.100
Stream #0:0(eng): Video: mjpeg, yuvj420p, 520x292, q=2-31, 200 kb/s, 90k tbn, 30 tbc
Metadata:
rotate : 90
handler_name : VideoHandler
Stream mapping:
Stream #0:0 -> #0:0 (h264 -> mjpeg)
Press [q] to stop, [?] for help
frame= 1 fps=0.0 q=0.0 Lsize=N/A time=00:00:00.03 bitrate=N/A dup=0 drop=57
video:19kB audio:0kB subtitle:0 global headers:0kB muxing overhead -100.113677%
Started POST "/api/v1/videos/create" for 69.42.0.13 at 2013-06-20 09:41:50 -0500
Command :: file -b --mime '/tmp/RackMultipart20130620-28711-187049m'
[paperclip] [ffmpeg] ffmpeg -i "/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l" 2>&1
[paperclip] [ffmpeg] Command Success
[paperclip] [ffmpeg] Making...
[paperclip] [ffmpeg] Building Destination File: 'RackMultipart20130620-28711-187049m20130620-28711-2x7b7l' + 'mp4'
[paperclip] [ffmpeg] Destination File Built
[paperclip] [ffmpeg] Adding Geometry
[paperclip] [ffmpeg] Extracting Target Dimensions
[paperclip] [ffmpeg] Target Size is Available
[paperclip] [ffmpeg] Keeping Aspect Ratio
[paperclip] [ffmpeg] Resize
[paperclip] [ffmpeg] Convert Options: 640x360
[paperclip] [ffmpeg] Adding Format
[paperclip] [ffmpeg] Adding Source
[paperclip] [ffmpeg] Building Parameters
[paperclip] [ffmpeg] -i :source -acodec aac -ac 2 -strict experimental -b:a 160k -vcodec libx264 -preset slow -profile:v baseline -level 30 -maxrate 10000000 -bufsize 10000000 -b:v 750k -f mp4 -threads 0 -s 640x360 -y :dest
Command :: ffmpeg -i '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l' -acodec aac -ac 2 -strict experimental -b:a 160k -vcodec libx264 -preset slow -profile:v baseline -level 30 -maxrate 10000000 -bufsize 10000000 -b:v 750k -f mp4 -threads 0 -s 640x360 -y '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p.mp4'
[paperclip] [qt-faststart] :source :dest
Command :: qt-faststart '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p.mp4' '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl.mp4'
[paperclip] [ffmpeg] ffmpeg -i "/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi06.mp4" 2>&1
[paperclip] [ffmpeg] Command Success
[paperclip] [ffmpeg] Making...
[paperclip] [ffmpeg] Building Destination File: 'RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi06' + 'mp4'
[paperclip] [ffmpeg] Destination File Built
[paperclip] [ffmpeg] Adding Geometry
[paperclip] [ffmpeg] Extracting Target Dimensions
[paperclip] [ffmpeg] Target Size is Available
[paperclip] [ffmpeg] Keeping Aspect Ratio
[paperclip] [ffmpeg] Resize
[paperclip] [ffmpeg] Convert Options: 480x270
[paperclip] [ffmpeg] Adding Format
[paperclip] [ffmpeg] Adding Source
[paperclip] [ffmpeg] Building Parameters
[paperclip] [ffmpeg] -i :source -acodec aac -ac 2 -strict experimental -b:a 160k -vcodec libx264 -preset slow -profile:v baseline -level 30 -maxrate 10000000 -bufsize 10000000 -b:v 750k -f mp4 -threads 0 -s 480x270 -y :dest
Command :: ffmpeg -i '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi06.mp4' -acodec aac -ac 2 -strict experimental -b:a 160k -vcodec libx264 -preset slow -profile:v baseline -level 30 -maxrate 10000000 -bufsize 10000000 -b:v 750k -f mp4 -threads 0 -s 480x270 -y '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi0620130620-28711-130rd1i.mp4'
[paperclip] [qt-faststart] :source :dest
Command :: qt-faststart '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi0620130620-28711-130rd1i.mp4' '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi0620130620-28711-130rd1i20130620-28711-snde6v.mp4'
[paperclip] [ffmpeg] ffmpeg -i "/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi06.mp4" 2>&1
[paperclip] [ffmpeg] Command Success
[paperclip] [ffmpeg] Making...
[paperclip] [ffmpeg] Building Destination File: 'RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi06' + 'jpg'
[paperclip] [ffmpeg] Destination File Built
[paperclip] [ffmpeg] Adding Geometry
[paperclip] [ffmpeg] Extracting Target Dimensions
[paperclip] [ffmpeg] Target Size is Available
[paperclip] [ffmpeg] Keeping Aspect Ratio
[paperclip] [ffmpeg] Resize
[paperclip] [ffmpeg] Convert Options: 160x90
[paperclip] [ffmpeg] Adding Format
[paperclip] [ffmpeg] Adding Source
[paperclip] [ffmpeg] Building Parameters
[paperclip] [ffmpeg] -ss 2 -i :source -s 160x90 -vframes 1 -f image2 -y :dest
Command :: ffmpeg -ss 2 -i '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi06.mp4' -s 160x90 -vframes 1 -f image2 -y '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi0620130620-28711-1bdslpu.jpg'
[paperclip] [ffmpeg] ffmpeg -i "/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi06.mp4" 2>&1
[paperclip] [ffmpeg] Command Success
[paperclip] [ffmpeg] Making...
[paperclip] [ffmpeg] Building Destination File: 'RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi06' + 'jpg'
[paperclip] [ffmpeg] Destination File Built
[paperclip] [ffmpeg] Adding Geometry
[paperclip] [ffmpeg] Extracting Target Dimensions
[paperclip] [ffmpeg] Target Size is Available
[paperclip] [ffmpeg] Keeping Aspect Ratio
[paperclip] [ffmpeg] Resize
[paperclip] [ffmpeg] Convert Options: 520x292
[paperclip] [ffmpeg] Adding Format
[paperclip] [ffmpeg] Adding Source
[paperclip] [ffmpeg] Building Parameters
[paperclip] [ffmpeg] -ss 2 -i :source -s 520x292 -vframes 1 -f image2 -y :dest
Command :: ffmpeg -ss 2 -i '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi06.mp4' -s 520x292 -vframes 1 -f image2 -y '/tmp/RackMultipart20130620-28711-187049m20130620-28711-2x7b7l20130620-28711-uibd1p20130620-28711-1tgemjl20130620-28711-15qsi0620130620-28711-1vp4al6.jpg'
[paperclip] Saving attachments.
答案 0 :(得分：2)
我刚刚撰写了一篇博文，内容涵盖encoding_h264_for_ios，其中展示了h.264编码的示例，这些编码在iOS硬件上有效且无效。我使用的具体命令行是：
ffmpeg -y -i INPUT.mov -c:v libx264
-pix_fmt yuv420p -preset:v slow
-profile:v baseline -crf 23
OUTPUT.m4v
如果我是你，我会尝试在命令行上对视频进行编码，并在没有Web界面的iOS硬件上测试它们。然后，逐步使用特定的命令行选项，直到找到打破iOS播放的那个。