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• How to reduce size of moov atom of H.264 movies to improve streaming start for smartphones ?

  14 avril 2013, par alebedev

  We run a video service streaming movies to smartphones (iOS&Android).
  We are encoding in H.264+AAC and using the mp4 container.
  We have a problem that long movies (60 minutes+) take a very long time to
  start playing and have tracked this down to the large size of moov
  atom for these movies.
  For 110 minute movies the atom is as large as 4.2Mb which obviously takes a long
  time to download to a smart-phone over 3G !

  Is there anyway to make the moov atom smaller ? We can reduce it bit
  by dropping the audio sampling rate, but obviously anything below 22kHz
  would not really be acceptable.

  We are using ffmpeg as the encoder, and MP4Box to move the metadata
  to the front of the file. Is there any way to get it to make
  a smaller moov ? Any other encoders out there which make a smaller moov ?

  For example...

  Big size (280 Mb, 1h 49min) streamable mp4 (h.264, AAC) file have a big header size (4.2 Mb). File was encoded by two pass ffmpeg and MP4Box for replacing metadata into beginning of the file :

  /usr/bin/ffmpeg -i /var/lib/encoder/incoming/2388 -aspect 320:210 -threads 8 -vcodec libx264 -profile baseline -level 13 -flags +loop+mv4 -cmp 256 -partitions +parti4x4+parti8x8+partp4x4+partp8x8+partb8x8 -me_method hex -subq 7 -trellis 1 -refs 5 -bf 0 -me_range 16 -g 250 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -qmin 10 -qmax 51 -qdiff 4 -b:v 270k -maxrate 270k -bufsize 270k -g 30 -passlogfile /tmp/mediaservice/3100/video-IPH.ffmpeg -an -f rawvideo -pass 1 -y /dev/null
  
  
  
  /usr/bin/ffmpeg -i /var/lib/encoder/incoming/2388 -aspect 320:210 -threads 8 -vcodec libx264 -profile baseline -level 13 -flags +loop+mv4 -cmp 256 -partitions +parti4x4+parti8x8+partp4x4+partp8x8+partb8x8 -me_method hex -subq 7 -trellis 1 -refs 5 -bf 0 -me_range 16 -g 250 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -qmin 10 -qmax 51 -qdiff 4 -b:v 270k -maxrate 270k -bufsize 270k -g 30 -passlogfile /tmp/mediaservice/3100/video-IPH.ffmpeg -acodec libfaac -ac 2 -b:a 32k -ar 44100 -f mp4 -pass 2 -y /var/lib/encoder/encoded/3100/video-IPH.mp4
  
  
  
  /usr/bin/MP4Box -quiet -tmp /tmp/mediaservice/3100/ -inter 500 /var/lib/encoder/encoded/3100/video-IPH.mp4

  Media info (audio sample rate = 44100) :

  General
  
  Count                                    : 278
  
  Count of stream of this kind             : 1
  
  Kind of stream                           : General
  
  Kind of stream                           : General
  
  Stream identifier                        : 0
  
  Count of video streams                   : 1
  
  Count of audio streams                   : 1
  
  Video_Format_List                        : AVC
  
  Video_Format_WithHint_List               : AVC
  
  Codecs Video                             : AVC
  
  Audio_Format_List                        : AAC
  
  Audio_Format_WithHint_List               : AAC
  
  Audio codecs                             : AAC LC
  
  Complete name                            : 1348645218_970458_2465.iph.mp4
  
  File name                                : 1348645218_970458_2465.iph.mp4
  
  File extension                           : mp4
  
  Format                                   : MPEG-4
  
  Format                                   : MPEG-4
  
  Format/Extensions usually used           : mp4 m4v m4a m4b m4p 3gpp 3gp 3gpp2 3g2 k3g jpm jpx mqv ismv isma f4v
  
  Commercial name                          : MPEG-4
  
  Format profile                           : Base Media
  
  Internet media type                      : video/mp4
  
  Codec ID                                 : isom
  
  Codec ID/Url                             : http://www.apple.com/quicktime/download/standalone.html
  
  Codec                                    : MPEG-4
  
  Codec                                    : MPEG-4
  
  Codec/Extensions usually used            : mp4 m4v m4a m4b m4p 3gpp 3gp 3gpp2 3g2 k3g jpm jpx mqv ismv isma f4v
  
  File size                                : 272703970
  
  File size                                : 260 MiB
  
  File size                                : 260 MiB
  
  File size                                : 260 MiB
  
  File size                                : 260 MiB
  
  File size                                : 260.1 MiB
  
  Duration                                 : 6556027
  
  Duration                                 : 1h 49mn
  
  Duration                                 : 1h 49mn 16s 27ms
  
  Duration                                 : 1h 49mn
  
  Duration                                 : 01:49:16.027
  
  Overall bit rate                         : 332767
  
  Overall bit rate                         : 333 Kbps
  
  Stream size                              : 4230761
  
  Stream size                              : 4.03 MiB (2%)
  
  Stream size                              : 4 MiB
  
  Stream size                              : 4.0 MiB
  
  Stream size                              : 4.03 MiB
  
  Stream size                              : 4.035 MiB
  
  Stream size                              : 4.03 MiB (2%)
  
  Proportion of this stream                : 0.01551
  
  HeaderSize                               : 4230683
  
  DataSize                                 : 268473217
  
  FooterSize                               : 70
  
  IsStreamable                             : Yes
  
  File last modification date              : UTC 2012-09-26 12:38:19
  
  File last modification date (local)      : 2012-09-26 21:38:19
  
  Writing application                      : Lavf54.6.100
  
  
  
  Video
  
  Count                                    : 201
  
  Count of stream of this kind             : 1
  
  Kind of stream                           : Video
  
  Kind of stream                           : Video
  
  Stream identifier                        : 0
  
  ID                                       : 1
  
  ID                                       : 1
  
  Format                                   : AVC
  
  Format/Info                              : Advanced Video Codec
  
  Format/Url                               : http://developers.videolan.org/x264.html
  
  Commercial name                          : AVC
  
  Format profile                           : Baseline@L1.3
  
  Format settings                          : 5 Ref Frames
  
  Format settings, CABAC                   : No
  
  Format settings, CABAC                   : No
  
  Format settings, ReFrames                : 5
  
  Format settings, ReFrames                : 5 frames
  
  Format settings, GOP                     : M=1, N=30
  
  Internet media type                      : video/H264
  
  Codec ID                                 : avc1
  
  Codec ID/Info                            : Advanced Video Coding
  
  Codec ID/Url                             : http://www.apple.com/quicktime/download/standalone.html
  
  Codec                                    : AVC
  
  Codec                                    : AVC
  
  Codec/Family                             : AVC
  
  Codec/Info                               : Advanced Video Codec
  
  Codec/Url                                : http://developers.videolan.org/x264.html
  
  Codec/CC                                 : avc1
  
  Codec profile                            : Baseline@L1.3
  
  Codec settings                           : 5 Ref Frames
  
  Codec settings, CABAC                    : No
  
  Codec_Settings_RefFrames                 : 5
  
  Duration                                 : 6556017
  
  Duration                                 : 01:49:16.017
  
  Bit rate                                 : 270000
  
  Bit rate                                 : 270 Kbps
  
  Width                                    : 480
  
  Width                                    : 480 pixels
  
  Height                                   : 270
  
  Height                                   : 270 pixels
  
  Pixel aspect ratio                       : 1.000
  
  Display aspect ratio                     : 1.778
  
  Display aspect ratio                     : 16:9
  
  Rotation                                 : 0.000
  
  Frame rate mode                          : CFR
  
  Frame rate mode                          : Constant
  
  FrameRate_Mode_Original                  : VFR
  
  Frame rate                               : 29.970
  
  Frame rate                               : 29.970 fps
  
  Frame count                              : 196484
  
  Resolution                               : 8
  
  Resolution                               : 8 bits
  
  Colorimetry                              : 4:2:0
  
  Color space                              : YUV
  
  Chroma subsampling                       : 4:2:0
  
  Bit depth                                : 8
  
  Bit depth                                : 8 bits
  
  Scan type                                : Progressive
  
  Scan type                                : Progressive
  
  Interlacement                            : PPF
  
  Interlacement                            : Progressive
  
  Bits/(Pixel*Frame)                       : 0.070
  
  Stream size                              : 220159060
  
  Stream size                              : 210 MiB (81%)
  
  Stream size                              : 210 MiB
  
  Stream size                              : 210 MiB
  
  Stream size                              : 210 MiB
  
  Stream size                              : 210.0 MiB
  
  Stream size                              : 210 MiB (81%)
  
  Proportion of this stream                : 0.80732
  
  Writing library                          : x264 - core 125
  
  Writing library                          : x264 core 125
  
  Writing library/Name                     : x264
  
  Writing library/Version                  : core 125
  
  Encoding settings                        : cabac=0 / ref=5 / deblock=1:0:0 / analyse=0x1:0x131 / me=hex / subme=7 / 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=8 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=0 / weightp=0 / keyint=30 / keyint_min=16 / scenecut=40 / intra_refresh=0 / rc_lookahead=30 / rc=2pass / mbtree=1 / bitrate=270 / ratetol=1.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / vbv_maxrate=270 / vbv_bufsize=270 / nal_hrd=none / ip_ratio=1.40 / aq=1:1.00
  
  Tagged date                              : UTC 2012-09-25 07:21:37
  
  
  
  Audio
  
  Count                                    : 169
  
  Count of stream of this kind             : 1
  
  Kind of stream                           : Audio
  
  Kind of stream                           : Audio
  
  Stream identifier                        : 0
  
  ID                                       : 2
  
  ID                                       : 2
  
  Format                                   : AAC
  
  Format/Info                              : Advanced Audio Codec
  
  Commercial name                          : AAC
  
  Format profile                           : LC
  
  Codec ID                                 : 40
  
  Codec                                    : AAC LC
  
  Codec                                    : AAC LC
  
  Codec/Family                             : AAC
  
  Codec/CC                                 : 40
  
  Duration                                 : 6556027
  
  Duration                                 : 1h 49mn
  
  Duration                                 : 1h 49mn 16s 27ms
  
  Duration                                 : 1h 49mn
  
  Duration                                 : 01:49:16.027
  
  Bit rate mode                            : VBR
  
  Bit rate mode                            : Variable
  
  Bit rate                                 : 58955
  
  Bit rate                                 : 59.0 Kbps
  
  Maximum bit rate                         : 270000
  
  Maximum bit rate                         : 270 Kbps
  
  Channel(s)                               : 2
  
  Channel(s)                               : 2 channels
  
  Channel positions                        : Front: L R
  
  Channel positions                        : 2/0/0
  
  Sampling rate                            : 44100
  
  Sampling rate                            : 44.1 KHz
  
  Samples count                            : 289120791
  
  Compression mode                         : Lossy
  
  Compression mode                         : Lossy
  
  Stream size                              : 48314149
  
  Stream size                              : 46.1 MiB (18%)
  
  Stream size                              : 46 MiB
  
  Stream size                              : 46 MiB
  
  Stream size                              : 46.1 MiB
  
  Stream size                              : 46.08 MiB
  
  Stream size                              : 46.1 MiB (18%)
  
  Proportion of this stream                : 0.17717
  
  Tagged date                              : UTC 2012-09-25 07:21:37

  Moov atom info (/moov/trak[0] - video, /moov/trak[1] - audio) sample rate 44100 :
  (look stsz and stts nodes in trak)

  Atom ftyp @ 0 of size: 32, ends @ 32
  
  Atom moov @ 32 of size: 4230651, ends @ 4230683
  
       Atom mvhd @ 40 of size: 108, ends @ 148
  
       Atom trak @ 148 of size: 868970, ends @ 869118
  
           Atom tkhd @ 156 of size: 92, ends @ 248
  
           Atom edts @ 248 of size: 36, ends @ 284
  
               Atom elst @ 256 of size: 28, ends @ 284
  
           Atom mdia @ 284 of size: 868834, ends @ 869118
  
               Atom mdhd @ 292 of size: 32, ends @ 324
  
               Atom hdlr @ 324 of size: 45, ends @ 369
  
               Atom minf @ 369 of size: 868749, ends @ 869118
  
                   Atom vmhd @ 377 of size: 20, ends @ 397
  
                   Atom dinf @ 397 of size: 36, ends @ 433
  
                       Atom dref @ 405 of size: 28, ends @ 433
  
                   Atom stbl @ 433 of size: 868685, ends @ 869118
  
                       Atom stsd @ 441 of size: 149, ends @ 590
  
                           Atom avc1 @ 457 of size: 133, ends @ 590
  
                               Atom avcC @ 543 of size: 47, ends @ 590
  
                       Atom stts @ 590 of size: 24, ends @ 614
  
                       Atom stss @ 614 of size: 26340, ends @ 26954
  
                       Atom stsc @ 26954 of size: 52, ends @ 27006
  
                       Atom stsz @ 27006 of size: 785956, ends @ 812962
  
                       Atom stco @ 812962 of size: 56156, ends @ 869118
  
       Atom trak @ 869118 of size: 3361468, ends @ 4230586
  
           Atom tkhd @ 869126 of size: 92, ends @ 869218
  
           Atom edts @ 869218 of size: 36, ends @ 869254
  
               Atom elst @ 869226 of size: 28, ends @ 869254
  
           Atom mdia @ 869254 of size: 3361332, ends @ 4230586
  
               Atom mdhd @ 869262 of size: 32, ends @ 869294
  
               Atom hdlr @ 869294 of size: 45, ends @ 869339
  
               Atom minf @ 869339 of size: 3361247, ends @ 4230586
  
                   Atom smhd @ 869347 of size: 16, ends @ 869363
  
                   Atom dinf @ 869363 of size: 36, ends @ 869399
  
                       Atom dref @ 869371 of size: 28, ends @ 869399
  
                   Atom stbl @ 869399 of size: 3361187, ends @ 4230586
  
                       Atom stsd @ 869407 of size: 91, ends @ 869498
  
                           Atom mp4a @ 869423 of size: 75, ends @ 869498
  
                               Atom esds @ 869459 of size: 39, ends @ 869498
  
                       **Atom stts @ 869498 of size: 2135816, ends @ 3005314**
  
                       Atom stsc @ 3005314 of size: 39712, ends @ 3045026
  
                       **Atom stsz @ 3045026 of size: 1129400, ends @ 4174426**
  
                       Atom stco @ 4174426 of size: 56160, ends @ 4230586
  
       Atom udta @ 4230586 of size: 97, ends @ 4230683
  
           Atom meta @ 4230594 of size: 89, ends @ 4230683
  
               Atom hdlr @ 4230606 of size: 33, ends @ 4230639
  
               Atom ilst @ 4230639 of size: 44, ends @ 4230683
  
                   Atom ©too @ 4230647 of size: 36, ends @ 4230683
  
                       Atom data @ 4230655 of size: 28, ends @ 4230683
  
  Atom mdat @ 4230683 of size: 268473217, ends @ 272703900
  
  Atom free @ 272703900 of size: 8, ends @ 272703908
  
  Atom free @ 272703908 of size: 62, ends @ 272703970
  
  ------------------------------------------------------
  
  Total size: 272703970 bytes; 50 atoms total. AtomicParsley version: 0.9.0 (utf8)
  
  Media data: 268473217 bytes; 4230753 bytes all other atoms (1.551% atom overhead).
  
  Total free atom space: 70 bytes; 0.000% waste. Padding available: 0 bytes.
  
  ------------------------------------------------------

  After reencoding this movie with audio sample rate 11025 header size much less :

  Media info (audio sample rate = 11025) : (crop duplicate info)

  General
  
  ***
  
  HeaderSize                               : 1276359
  
  
  
  Video
  
  ***
  
  
  
  Audio
  
  Count                                    : 169
  
  Count of stream of this kind             : 1
  
  Kind of stream                           : Audio
  
  Kind of stream                           : Audio
  
  Stream identifier                        : 0
  
  ID                                       : 2
  
  ID                                       : 2
  
  Format                                   : AAC
  
  Format/Info                              : Advanced Audio Codec
  
  Commercial name                          : AAC
  
  Format profile                           : LC
  
  Codec ID                                 : 40
  
  Codec                                    : AAC LC
  
  Codec                                    : AAC LC
  
  Codec/Family                             : AAC
  
  Codec/CC                                 : 40
  
  Duration                                 : 6556132
  
  Duration                                 : 1h 49mn
  
  Duration                                 : 1h 49mn 16s 132ms
  
  Duration                                 : 1h 49mn
  
  Duration                                 : 01:49:16.132
  
  Bit rate mode                            : VBR
  
  Bit rate mode                            : Variable
  
  Bit rate                                 : 37991
  
  Bit rate                                 : 38.0 Kbps
  
  Maximum bit rate                         : 128000
  
  Maximum bit rate                         : 128 Kbps
  
  Channel(s)                               : 2
  
  Channel(s)                               : 2 channels
  
  Channel positions                        : Front: L R
  
  Channel positions                        : 2/0/0
  
  Sampling rate                            : 11025
  
  Sampling rate                            : 11.025 KHz
  
  Samples count                            : 72281355
  
  Compression mode                         : Lossy
  
  Compression mode                         : Lossy
  
  Stream size                              : 31134257
  
  Stream size                              : 29.7 MiB (12%)
  
  Stream size                              : 30 MiB
  
  Stream size                              : 30 MiB
  
  Stream size                              : 29.7 MiB
  
  Stream size                              : 29.69 MiB
  
  Stream size                              : 29.7 MiB (12%)
  
  Proportion of this stream                : 0.12327
  
  Tagged date                              : UTC 2012-09-25 13:20:28

  Moov atom info (/moov/trak[0] - video, /moov/trak[1] - audio) sample rate 11025 :

  Atom ftyp @ 0 of size: 32, ends @ 32
  
  Atom moov @ 32 of size: 1276327, ends @ 1276359
  
       Atom mvhd @ 40 of size: 108, ends @ 148
  
       Atom trak @ 148 of size: 821662, ends @ 821810
  
           Atom tkhd @ 156 of size: 92, ends @ 248
  
           Atom edts @ 248 of size: 36, ends @ 284
  
               Atom elst @ 256 of size: 28, ends @ 284
  
           Atom mdia @ 284 of size: 821526, ends @ 821810
  
               Atom mdhd @ 292 of size: 32, ends @ 324
  
               Atom hdlr @ 324 of size: 45, ends @ 369
  
               Atom minf @ 369 of size: 821441, ends @ 821810
  
                   Atom vmhd @ 377 of size: 20, ends @ 397
  
                   Atom dinf @ 397 of size: 36, ends @ 433
  
                       Atom dref @ 405 of size: 28, ends @ 433
  
                   Atom stbl @ 433 of size: 821377, ends @ 821810
  
                       Atom stsd @ 441 of size: 149, ends @ 590
  
                           Atom avc1 @ 457 of size: 133, ends @ 590
  
                               Atom avcC @ 543 of size: 47, ends @ 590
  
                       Atom stts @ 590 of size: 24, ends @ 614
  
                       Atom stss @ 614 of size: 26340, ends @ 26954
  
                       Atom stsc @ 26954 of size: 52, ends @ 27006
  
                       Atom stsz @ 27006 of size: 785956, ends @ 812962
  
                       Atom stco @ 812962 of size: 8848, ends @ 821810
  
       Atom trak @ 821810 of size: 454452, ends @ 1276262
  
           Atom tkhd @ 821818 of size: 92, ends @ 821910
  
           Atom edts @ 821910 of size: 36, ends @ 821946
  
               Atom elst @ 821918 of size: 28, ends @ 821946
  
           Atom mdia @ 821946 of size: 454316, ends @ 1276262
  
               Atom mdhd @ 821954 of size: 32, ends @ 821986
  
               Atom hdlr @ 821986 of size: 45, ends @ 822031
  
               Atom minf @ 822031 of size: 454231, ends @ 1276262
  
                   Atom smhd @ 822039 of size: 16, ends @ 822055
  
                   Atom dinf @ 822055 of size: 36, ends @ 822091
  
                       Atom dref @ 822063 of size: 28, ends @ 822091
  
                   Atom stbl @ 822091 of size: 454171, ends @ 1276262
  
                       Atom stsd @ 822099 of size: 91, ends @ 822190
  
                           Atom mp4a @ 822115 of size: 75, ends @ 822190
  
                               Atom esds @ 822151 of size: 39, ends @ 822190
  
                       Atom stts @ 822190 of size: 161368, ends @ 983558
  
                       Atom stsc @ 983558 of size: 1480, ends @ 985038
  
                       Atom stsz @ 985038 of size: 282372, ends @ 1267410
  
                       Atom stco @ 1267410 of size: 8852, ends @ 1276262
  
       Atom udta @ 1276262 of size: 97, ends @ 1276359
  
           Atom meta @ 1276270 of size: 89, ends @ 1276359
  
               Atom hdlr @ 1276282 of size: 33, ends @ 1276315
  
               Atom ilst @ 1276315 of size: 44, ends @ 1276359
  
                   Atom ©too @ 1276323 of size: 36, ends @ 1276359
  
                       Atom data @ 1276331 of size: 28, ends @ 1276359
  
  Atom mdat @ 1276359 of size: 251293325, ends @ 252569684
  
  Atom free @ 252569684 of size: 8, ends @ 252569692
  
  Atom free @ 252569692 of size: 62, ends @ 252569754
  
  ------------------------------------------------------
  
  Total size: 252569754 bytes; 50 atoms total. AtomicParsley version: 0.9.0 (utf8)
  
  Media data: 251293325 bytes; 1276429 bytes all other atoms (0.505% atom overhead).
  
  Total free atom space: 70 bytes; 0.000% waste. Padding available: 0 bytes.
  
  ------------------------------------------------------

  On slow connection this movie start playing after 30-40 seconds until header info (4.2 Mb) downloading. I need that movie start playing fast as it possible. And i have next questions :

  1. How reduce size of movie header ?

  2. How reduce size of
     /moov[0]/trak[1]/mdia[0]/minf[0]/stbl[0] and why it so big when
     sample rate 44100 ?

• The new GDPR data protection regulation and potential consequences on Piwik

  7 septembre 2017, par Piwik Core Team — About, Privacy

  GDPR is a new data protection related regulation in Europe. GDPR stands for General Data Protection Regulation.

  The purpose of this European regulation is to strengthen and unify data protection for all individuals within the European Union. This also includes entities outside Europe willing to do business with European citizens. GDPR is a set of processes you need to follow within your organization to protect the privacy of European citizens.

  GDPR will start to apply in May 2018. It is recognized to be dissuasive because of the potential penalty of up to 4% of the yearly turnover, in case of infringement.

  Many articles have been written about GDPR including our previous article. Few of them are explaining how it will affect web analytics vendors : this is what this article is about.

  Am I really impacted by GDPR if I am a Piwik user ?

  As Piwik can collect personal data, the answer is yes. Piwik analytics data is impacted by the GDPR.

  As GDPR is a general concept, we decided from the official guidelines to assume what will be the potential consequences on the use of Piwik.

  There are 2 potential scenarios we can identify :

  • 1 – You are collecting personal data with Piwik
  • 2 – You are not collecting personal data with Piwik

  1 – Personal data collection with Piwik

  According to GDPR : IP addresses, cookies, UserID are personal data.

  IP addresses are personal data, so you will have to anonymize them unless you receive explicit consent from the visitor. Please view the following article in order to learn : how can I anonymize IP addresses in Piwik ?

  According to GDPR, cookies are personal data too. But as all cookies are not created equal it may be possible that some need to require user consent whereas other not. Whatever will be the final decision, you can learn about the first-party cookies created by Piwik and how to disable all tracking cookies in Piwik ?

  User ID, you are impacted if the User ID you assign is specific to an individual or if you can cross the User ID data further and find back the individual personal data.

  Any extra personal data you may collect with Piwik, it could be for example : first names, family names, e-mail address… You are able to collect such data using custom dimensions, custom variables…

  What are the rules I have to comply with ?

  By collecting personal data, you will have to respect EU citizens rights, which include :

  • The possibility for them to view the data you collected on them
  • The possibility to rectify some data concerning them
  • The possibility to delete their data when they request about it

  As you can imagine, for the first obligation, you will have to export all the data. So if a user is requesting it, you will have to export the data linked to his IP address(es). It can be easily exported as a .csv file for example.
  In order to do that, just create a segment according to the IP address of the user who requested it and then export the “Visitor log” report.
  If the personal data is not linked with the IP address but other attributes such as User ID or a custom dimension, you can provide the same data export by using the segment function and filtering on the personal data field.

  The data edit and deletion process on Piwik is a bit trickier as it currently requires administration system skills. We are planning to develop a new plugin for GDPR compliance (which will be available for free on the Marketplace). This plugin will let you edit and easily delete data of a particular user. Currently you can delete a specific user’s data by accessing the Piwik database and directly delete the different records for this specific user.

  2 – You are not collecting personal data with Piwik

  Unfortunately it is not because you do not collect personal data that you will not be affected by GDPR.
  The details of GDPR are not confirmed yet and GDPR could involve enabling the DoNotTrack setting by default on all browsers.
  Yes, you read it well, by default, unless the internet user uncheck this option, Piwik respecting DoNoTrack would not be able to track any user. If one needed to collect data anyway, Piwik Log Analytics and server-side tracking can be considered.

  If you need help regarding how to set up your Piwik installation in order to be GDPR compliant :

  Contact us

  Do you have a Piwik experience you would like to share with the community ? Please share it with us by contacting Piwik core team.

• Typesetting

  9 juin 2010, par Mikko Koppanen — Imagick, PHP stuff

  Ever had the situation where you have a piece of string which you need to overlay on an image ? Maybe a situation where the area reserved for the string is known in pixels but you need to know the font size to fill most of the area ? Think no more !

  Here is a small example of how to fit a certain piece of a string on to an area of which you know the width and the height or only the width. The magic happens through the ImageMagick CAPTION : format. You can see from the example images how the parameters actually affect the image.

  php

  < view plain text >

  1. < ?php
  2.  
  3. /* How wide is our image */
  4. $image_width = 200 ;
  5.  
  6. /* Give zero for autocalculating the height */
  7. $image_height = 200 ;
  8.  
  9. /* Specify the text */
  10. $text = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit.
  11.     Mauris lectus mi, mattis non, euismod vel, sagittis nec, ipsum." ;
  12.  
  13. /* Instanciate imagick */
  14. $im = new Imagick() ;
  15.  
  16. /* Create new image using caption : pseudo format */
  17. $im->newPseudoImage( $image_width, $image_height, "caption :" . $text ) ;
  18.  
  19. /* Put 1px border around the image */
  20. $im->borderImage( ’black’, 1, 1 ) ;
  21.  
  22. /* PNG format */
  23. $im->setImageFormat( "png")  ;
  24.  
  25. /* Output */
  26. header( "Content-Type : image/png" ) ;
  27. echo $im ;
  28.  
  29.  ?>

  Here is image with width 100 and height 0 :

  

  Width 100 Height 50 :

  

  Width 200 Height 200 (as you can see the font size is now larger) :