Playing videos on iPhone after video conversion using ffmpeg

Question

It is a backend API(developed in Ruby on Rails) which is used by iphone and android mobiles to upload the videos. API is converting uploaded videos to MP4 format. I am using paperclip-ffmpeg gem for video conversion at backend. Here is what I used:

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

Problems I am facing are:

When user uploads videos from android mobile it works perfect on android but does not play on iPhone. One more strange thing happens when user upload videos from iPhone, then it play perfect just after video upload, but after some time(2 or 3 hours) it stops to play those videos.

How can I get rid of both these issues? Any suggestion would be appreciated. Thanks

@Michael, here is the detailed log for the video conversion uploaded by android mobile

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.

Answer 1

I just wrote a blog post that covers encoding_h264_for_ios that shows examples of h.264 encoding that do and do not work on iOS hardware. The specific command line that I use is this:

ffmpeg -y -i INPUT.mov -c:v libx264
  -pix_fmt yuv420p -preset:v slow
  -profile:v baseline -crf 23
  OUTPUT.m4v

If I were you, I would try to encode the videos on the command line and test them on iOS hardware without the web interface. Then, go step by step with specific command line options until you found the one that was breaking the iOS playback.