Recherche avancée

Sur d’autres sites (11058)

• Revision 3327 : Le modèle pour les images prenant en compte les largeurs et autres ...

  25 avril 2010, par kent1 — Log

  Le modèle pour les images prenant en compte les largeurs et autres hauteurs fixées au modèle

• Fixing A/V sync issues with RTP/RTCP sent from mediasoup

  10 décembre 2017, par artushin

  A little background : I’m attempting to record a webrtc call being made through the mediasoup v2 SFU. I’m using mediasoup’s room.createRtpStreamer() method to generate a stream which mirrors RTP/RTCP to ffmpeg. Two streamers are created for audio and video within 30ms of each other and begin broadcasting. FFmpeg then spins up and starts accepting. Pretty sure RTCP is working since ffmpeg is always starting with a keyframe despite being started after the streamer begins broadcasting.

  The problem is that I encounter audio/video desynchronization with seemingly random offsets. My current theory is that this offset is based on how old the last keyframe is that RTCP requests to start the stream. See below for ffmpeg configuration and output but my question is : what ffmpeg arguments can I use to adjust the video frame timestamps to match the audio frame timestamps or vice versa ? I’ve messed around with -map 0:0,0:1 -map 0:1,0:1 but it doesn’t seem to do what I’m looking for.

  ffmpeg flags :

  '-y',
  
  '-loglevel',
  
  'debug',
  
  '-dump',
  
  '-protocol_whitelist',
  
  'file,crypto,udp,rtp,data',
  
  '-analyzeduration',
  
  '20M',
  
  '-probesize',
  
  '20M',
  
  '-i',
  
  `data:text/plain;base64,${sdp.toString('base64')}`,
  
  '-fflags',
  
  '+genpts',
  
  '-vcodec',
  
  'copy',
  
  '-acodec',
  
  'aac',
  
  '-bsf:v',
  
  'h264_mp4toannexb',
  
  '-start_number',
  
  '0',
  
  '-hls_list_size',
  
  '2147480000',
  
  '-hls_wrap',
  
  '0',
  
  '-hls_time',
  
  '10',

  SDP used for input (template) :

  v=0
  
  o=- 0 0 IN IP4 <%=ip %>
  
  s=title
  
  c=IN IP4 <%=ip %>
  
  m=audio <%=audioPort %> RTP/AVPF <%=audioPayload %>
  
  a=sendrecv
  
  a=rtcp-mux
  
  a=rtpmap:<%=audioPayload %> opus/48000/2
  
  a=fmtp:<%=audioPayload %> minptime=10; useinbandfec=1
  
  m=video <%=videoPort %> RTP/AVPF <%=videoPayload %>
  
  a=sendrecv
  
  a=rtcp-mux
  
  a=rtpmap:<%=videoPayload %> H264/90000
  
  a=rtcp-fb:<%=videoPayload %> ccm fir
  
  a=rtcp-fb:<%=videoPayload %> nack
  
  a=rtcp-fb:<%=videoPayload %> nack pli
  
  a=rtcp-fb:<%=videoPayload %> goog-remb
  
  a=rtcp-fb:<%=videoPayload %> transport-cc
  
  a=fmtp:<%=videoPayload %> level-asymmetry-allowed=1;packetization-mode=1

  ffmpeg output - garbled with some timestamps

  1512775954585 - stderr: ffmpeg version 3.4 Copyright (c) 2000-2017 the FFmpeg developers
  
    built with Apple LLVM version 9.0.0 (clang-900.0.38)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/3.4 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-gpl --enable-ffplay --enable-libmp3lame --enable-libvpx --enable-libx264 --enable-libxvid --enable-opencl --enable-videotoolbox --disable-lzma
  
  1512775954587 - stderr:   libavutil      55. 78.100 / 55. 78.100
  
    libavcodec     57.107.100 / 57.107.100
  
    libavformat    57. 83.100 / 57. 83.100
  
    libavdevice    57. 10.100 / 57. 10.100
  
  1512775954587 - stderr:   libavfilter     6.107.100 /  6.107.100
  
    libavresample   3.  7.  0 /  3.  7.  0
  
    libswscale      4.  8.100 /  4.  8.100
  
    libswresample   2.  9.100 /  2.  9.100
  
    libpostproc    54.  7.100 / 54.  7.100
  
  Splitting the commandline.
  
  Reading option '-y' ... matched as option 'y' (overwrite output files) with argument '1'.
  
  Reading option '-loglevel' ... matched as option 'loglevel' (set logging level) with argument 'debug'.
  
  Reading option '-dump' ... matched as option 'dump' (dump each input packet) with argument '1'.
  
  Reading option '-protocol_whitelist' ...1512775954589 - stderr:  matched as AVOption 'protocol_whitelist' with argument 'file,crypto,udp,rtp,data'.
  
  Reading option '-analyzeduration' ...1512775954590 - stderr:  matched as AVOption 'analyzeduration' with argument '20M'.
  
  Reading option '-probesize' ...1512775954590 - stderr:  matched as AVOption 'probesize' with argument '20M'.
  
  Reading option '-i' ... matched as input url with argument 'data:text/plain;base64,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'.
  
  Reading option '-fflags' ...1512775954591 - stderr:  matched as AVOption 'fflags' with argument '+genpts'.
  
  Reading option '-vcodec' ... matched as option 'vcodec' (force video codec ('copy' to copy stream)) with argument 'copy'.
  
  Reading option '-acodec' ... matched as option 'acodec' (force audio codec ('copy' to copy stream)) with argument 'aac'.
  
  Reading option '-vsync' ... matched as option 'vsync' (video sync method) with argument '0'.
  
  Reading option '-map' ... matched as option 'map' (set input stream mapping) with argument '0:0,0:1'.
  
  Reading option '-map' ... matched as option 'map' (set input stream mapping) with argument '0:1,0:1'.
  
  Reading option '-bsf:v' ... matched as option 'bsf' (A comma-separated list of bitstream filters) with argument 'h264_mp4toannexb'.
  
  Reading option '-start_number' ...1512775954591 - stderr:  matched as AVOption 'start_number' with argument '0'.
  
  Reading option '-hls_list_size' ...1512775954591 - stderr:  matched as AVOption 'hls_list_size' with argument '2147480000'.
  
  Reading option '-hls_wrap' ... matched as AVOption 'hls_wrap' with argument '0'.
  
  Reading option '-hls_time' ...1512775954591 - stderr:  matched as AVOption 'hls_time' with argument '10'.
  
  Reading option '/tmp/archive/e0c92fa0-dad5-11e7-8687-090dda95b1a4_10e1c990-dc70-11e7-888d-9f39ca0c79bc/1512775954465.m3u8' ... matched as output url.
  
  Finished splitting the commandline.
  
  Parsing a group of options: global .
  
  Applying option y (overwrite output files) with argument 1.
  
  1512775954592 - stderr: Applying option loglevel (set logging level) with argument debug.
  
  Applying option dump (dump each input packet) with argument 1.
  
  Applying option vsync (video sync method) with argument 0.
  
  Successfully parsed a group of options.
  
  Parsing a group of options: input url data:text/plain;base64,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.
  
  Successfully parsed a group of options.
  
  Opening an input file: data:text/plain;base64,dj0wCm89LSAwIDAgSU4gSVA0IDEyNy4wLjAuMQpzPWUwYzkyZmEwLWRhZDUtMTFlNy04Njg3LTA5MGRkYTk1YjFhNCBmb29ib2FyCmM9SU4gSVA0IDEyNy4wLjAuMQptPWF1ZGlvIDIwMDAwIFJUUC9BVlBGIDEwMAphPXNlbmRyZWN2CmE9cnRjcC1tdXgKYT1ydHBtYXA6MTAwIG9wdXMvNDgwMDAvMgphPWZtdHA6MTAwIG1pbnB0aW1lPTEwOyB1c2VpbmJhbmRmZWM9MQptPXZpZGVvIDIwMDAyIFJUUC9BVlBGIDEwMQphPXNlbmRyZWN2CmE9cnRjcC1tdXgKYT1ydHBtYXA6MTAxIEgyNjQvOTAwMDAKYT1ydGNwLWZiOjEwMSBjY20gZmlyCmE9cnRjcC1mYjoxMDEgbmFjawphPXJ0Y3AtZmI6MTAxIG5hY2sgcGxpCmE9cnRjcC1mYjoxMDEgZ29vZy1yZW1iCmE9cnRjcC1mYjoxMDEgdHJhbnNwb3J0LWNjCmE9Zm10cDoxMDEgbGV2ZWwtYXN5bW1ldHJ5LWFsbG93ZWQ9MTtwYWNrZXRpemF0aW9uLW1vZGU9MTtwcm9maWxlLWxldmVsLWlkPTQyZTAxZgo=.
  
  1512775954592 - stderr: [NULL @ 0x7f81fd000000] Opening 'data:text/plain;base64,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' for reading
  
  1512775954593 - stderr: [data @ 0x7f81fca001a0] Content-type: text/plain
  
  {"level":"info","time":"Dec 8, 2017 11:32 PM","message":"ffmpeg started"}
  
  1512775954595 - stderr: [sdp @ 0x7f81fd000000] Format sdp probed with size=2048 and score=50
  
  1512775954598 - stderr: [sdp @ 0x7f81fd000000] audio codec set to: opus
  
  [sdp @ 0x7f81fd000000] audio samplerate set to: 48000
  
  [sdp @ 0x7f81fd000000] audio channels set to: 2
  
  1512775954639 - stderr: [sdp @ 0x7f81fd000000] video codec set to: h264
  
  [sdp @ 0x7f81fd000000] RTP Packetization Mode: 1
  
  [sdp @ 0x7f81fd000000] RTP Profile IDC: 42 Profile IOP: e0 Level: 1f
  
  [udp @ 0x7f81fcb007e0] end receive buffer size reported is 65536
  
  [udp @ 0x7f81fbe00180] end receive buffer size reported is 65536
  
  [sdp @ 0x7f81fd000000] setting jitter buffer size to 500
  
  [udp @ 0x7f81fbe00680] end receive buffer size reported is 65536
  
  [udp @ 0x7f81fbe00740] end receive buffer size reported is 65536
  
  [sdp @ 0x7f81fd000000] setting jitter buffer size to 500
  
  [sdp @ 0x7f81fd000000] Before avformat_find_stream_info() pos: 479 bytes read:479 seeks:0 nb_streams:2
  
  {"level":"info","time":"Dec 8, 2017 11:32 PM","message":"new active speaker","activePeer":"9f05d96a-9641-4c63-8f0e-486b98e48eb5"}
  
  1512775954773 - stderr: [AVBSFContext @ 0x7f81fc8018e0] nal_unit_type: 7, nal_ref_idc: 3
  
  [AVBSFContext @ 0x7f81fc8018e0] nal_unit_type: 8, nal_ref_idc: 3
  
  [AVBSFContext @ 0x7f81fc8018e0] nal_unit_type: 5, nal_ref_idc: 3
  
  1512775954774 - stderr: [h264 @ 0x7f8200000c00] nal_unit_type: 7, nal_ref_idc: 3
  
  1512775954774 - stderr: [h264 @ 0x7f8200000c00] nal_unit_type: 8, nal_ref_idc: 3
  
  1512775954774 - stderr: [h264 @ 0x7f8200000c00] nal_unit_type: 5, nal_ref_idc: 3
  
  1512775954774 - stderr: [h264 @ 0x7f8200000c00] Reinit context to 640x480, pix_fmt: yuv420p
  
  1512775954801 - stderr: [h264 @ 0x7f8200000c00] nal_unit_type: 1, nal_ref_idc: 3
  
  1512775954939 - stderr: [h264 @ 0x7f8200000c00] nal_unit_type: 7, nal_ref_idc: 3
  
  1512775954939 - stderr: [h264 @ 0x7f8200000c00] nal_unit_type: 8, nal_ref_idc: 3
  
  1512775954940 - stderr: [h264 @ 0x7f8200000c00] nal_unit_type: 5, nal_ref_idc: 3
  
  1512775955003 - stderr: [h264 @ 0x7f8200000c00] nal_unit_type: 1, nal_ref_idc: 3
  
  1512775955999 - stderr:     Last message repeated 3 times
  
  [sdp @ 0x7f81fd000000] All info found
  
  1512775955999 - stderr: [sdp @ 0x7f81fd000000] rfps: 29.750000 0.019566
  
  [sdp @ 0x7f81fd000000] rfps: 29.833333 0.015263
  
  [sdp @ 0x7f81fd000000] rfps: 29.916667 0.011503
  
  1512775955999 - stderr: [sdp @ 0x7f81fd000000] rfps: 30.000000 0.008285
  
  [sdp @ 0x7f81fd000000] rfps: 31.000000 0.011990
  
      Last message repeated 1 times
  
  [sdp @ 0x7f81fd000000] rfps: 29.970030 0.009380
  
  [sdp @ 0x7f81fd000000] After avformat_find_stream_info() pos: 479 bytes read:479 seeks:0 frames:98
  
  1512775956000 - stderr: Input #0, sdp, from 'data:text/plain;base64,dj0wCm89LSAwIDAgSU4gSVA0IDEyNy4wLjAuMQpzPWUwYzkyZmEwLWRhZDUtMTFlNy04Njg3LTA5MGRkYTk1YjFhNCBmb29ib2FyCmM9SU4gSVA0IDEyNy4wLjAuMQptPWF1ZGlvIDIwMDAwIFJUUC9BVlBGIDEwMAphPXNlbmRyZWN2CmE9cnRjcC1tdXgKYT1ydHBtYXA6MTAwIG9wdXMvNDgwMDAvMgphPWZtdHA6MTAwIG1pbnB0aW1lPTEwOyB1c2VpbmJhbmRmZWM9MQptPXZpZGVvIDIwMDAyIFJUUC9BVlBGIDEwMQphPXNlbmRyZWN2CmE9cnRjcC1tdXgKYT1ydHBtYXA6MTAxIEgyNjQvOTAwMDAKYT1ydGNwLWZiOjEwMSBjY20gZmlyCmE9cnRjcC1mYjoxMDEgbmFjawphPXJ0Y3AtZmI6MTAxIG5hY2sgcGxpCmE9cnRjcC1mYjoxMDEgZ29vZy1yZW1iCmE9cnRjcC1mYjoxMDEgdHJhbnNwb3J0LWNjCmE9Zm10cDoxMDEgbGV2ZWwtYXN5bW1ldHJ5LWFsbG93ZWQ9MTtwYWNrZXRpemF0aW9uLW1vZGU9MTtwcm9maWxlLWxldmVsLWlkPTQyZTAxZgo=':
  
  1512775956000 - stderr:   Metadata:
  
      title           : e0c92fa0-dad5-11e7-8687-090dda95b1a4 fooboar
  
    Duration: N/A, start: 0.000000, bitrate: N/A
  
      Stream #0:0, 70, 1/48000: Audio: opus, 48000 Hz, stereo, fltp1512775956000 - stderr:
  
      Stream #0:1, 28, 1/90000: Video: h264 (Constrained Baseline), 1 reference frame, yuv420p(progressive, left), 640x480, 0/1, 30 tbr, 90k tbn, 180k tbc
  
  1512775956000 - stderr: Successfully opened the file.
  
  Parsing a group of options: output url /tmp/archive/e0c92fa0-dad5-11e7-8687-090dda95b1a4_10e1c990-dc70-11e7-888d-9f39ca0c79bc/1512775954465.m3u8.
  
  Applying option vcodec (force video codec ('copy' to copy stream)) with argument copy.
  
  Applying option acodec (force audio codec ('copy' to copy stream)) with argument aac.
  
  Applying option map (set input stream mapping) with argument 0:0,0:1.
  
  Applying option map (set input stream mapping) with argument 0:1,0:1.
  
  Applying option bsf:v (A comma-separated list of bitstream filters) with argument h264_mp4toannexb.
  
  Successfully parsed a group of options.
  
  1512775956000 - stderr: Opening an output file: /tmp/archive/e0c92fa0-dad5-11e7-8687-090dda95b1a4_10e1c990-dc70-11e7-888d-9f39ca0c79bc/1512775954465.m3u8.
  
  1512775956000 - stderr: Successfully opened the file.
  
  1512775956001 - stderr: [AVBSFContext @ 0x7f81fcb020a0] The input looks like it is Annex B already
  
  Stream mapping:
  
  1512775956001 - stderr:   Stream #0:0 -> #0:0 [sync #0:1] (opus (native) -> aac (native))
  
    Stream #0:1 -> #0:1 (copy)
  
  Press [q] to stop, [?] for help
  
  cur_dts is invalid (this is harmless if it occurs once at the start per stream)
  
  stream #0:
  
    keyframe=1
  
    duration=0.000
  
    dts=0.000  pts=0.000
  
    size=82
  
  1512775956001 - stderr: [SWR @ 0x7f820001e600] Using fltp internally between filters
  
  1512775956002 - stderr: detected 8 logical cores
  
  1512775956003 - stderr: [graph_0_in_0_0 @ 0x7f81fc90dfc0] Setting 'time_base' to value '1/48000'
  
  [graph_0_in_0_0 @ 0x7f81fc90dfc0] Setting 'sample_rate' to value '48000'
  
  1512775956003 - stderr: [graph_0_in_0_0 @ 0x7f81fc90dfc0] Setting 'sample_fmt' to value 'fltp'
  
  [graph_0_in_0_0 @ 0x7f81fc90dfc0] Setting 'channel_layout' to value '0x3'
  
  [graph_0_in_0_0 @ 0x7f81fc90dfc0] tb:1/48000 samplefmt:fltp samplerate:48000 chlayout:0x3
  
  [format_out_0_0 @ 0x7f81fc914da0] Setting 'sample_fmts' to value 'fltp'
  
  [format_out_0_0 @ 0x7f81fc914da0] Setting 'sample_rates' to value '96000|88200|64000|48000|44100|32000|24000|22050|16000|12000|11025|8000|7350'
  
  1512775956004 - stderr: [AVFilterGraph @ 0x7f81fbd02200] query_formats: 4 queried, 9 merged, 0 already done, 0 delayed
  
  1512775956007 - stderr: [hls @ 0x7f81fd80f000] Opening '/tmp/archive/e0c92fa0-dad5-11e7-8687-090dda95b1a4_10e1c990-dc70-11e7-888d-9f39ca0c79bc/15127759544650.ts' for writing
  
  [file @ 0x7f81fbf01ee0] Setting default whitelist 'file,crypto'
  
  1512775956007 - stderr: [mpegts @ 0x7f81fd877800] muxrate VBR, pcr every 9000 pkts, sdt every 2147483647, pat/pmt every 2147483647 pkts
  
  Output #0, hls, to '/tmp/archive/e0c92fa0-dad5-11e7-8687-090dda95b1a4_10e1c990-dc70-11e7-888d-9f39ca0c79bc/1512775954465.m3u8':
  
    Metadata:
  
      title           : e0c92fa0-dad5-11e7-8687-090dda95b1a4 fooboar
  
      encoder         : Lavf57.83.100
  
  1512775956007 - stderr:     Stream #0:0, 0, 1/90000: Audio: aac (LC), 48000 Hz, stereo, fltp, delay 1024, 128 kb/s
  
      Metadata:
  
        encoder         : Lavc57.107.100 aac
  
      Stream #0:1, 0, 1/90000: Video: h264 (Constrained Baseline), 1 reference frame, yuv420p(progressive, left), 640x480 (0x0), 0/1, q=2-31, 30 tbr, 90k tbn, 90k tbc
  
  cur_dts is invalid (this is harmless if it occurs once at the start per stream)
  
  1512775956007 - stderr:     Last message repeated 1 times
  
  stream #0:
  
    keyframe=1
  
    duration=0.000
  
    dts=0.020  pts=0.020
  
    size=79
  
  1512775956007 - stderr: cur_dts is invalid (this is harmless if it occurs once at the start per stream)
  
      Last message repeated 1 times
  
  stream #0:
  
    keyframe=1
  
    duration=0.000
  
  1512775956007 - stderr:   dts=0.040  pts=0.040
  
    size=75
  
  1512775956014 - stderr: cur_dts is invalid (this is harmless if it occurs once at the start per stream)
  
  stream #0:
  
    keyframe=1
  
    duration=0.000
  
    dts=0.0601512775956014 - stderr:   pts=0.060
  
    size=81
  
  1512775956017 - stderr: cur_dts is invalid (this is harmless if it occurs once at the start per stream)
  
  stream #0:
  
    keyframe=1
  
    duration=0.000
  
    dts=0.080  pts=0.080
  
    size=76
  
  1512775956022 - stderr: cur_dts is invalid (this is harmless if it occurs once at the start per stream)
  
  stream #0:
  
    keyframe=1
  
    duration=0.000
  
    dts=0.1001512775956022 - stderr:   pts=0.100
  
    size=79
  
  1512775956023 - stderr: cur_dts is invalid (this is harmless if it occurs once at the start per stream)
  
  stream #0:
  
    keyframe=1
  
  1512775956023 - stderr:   duration=0.000
  
    dts=0.120  pts=0.120
  
    size=95
  
  1512775956024 - stderr: cur_dts is invalid (this is harmless if it occurs once at the start per stream)
  
  1512775956024 - stderr: stream #0:
  
    keyframe=1
  
    duration=0.000
  
    dts=0.140  pts=0.140
  
    size=93
  
  1512775956025 - stderr: cur_dts is invalid (this is harmless if it occurs once at the start per stream)
  
  stream #0:
  
    keyframe=1
  
  1512775956025 - stderr:   duration=0.000
  
    dts=0.160  pts=0.160
  
    size=94
  
  1512775956026 - stderr: cur_dts is invalid (this is harmless if it occurs once at the start per stream)
  
  stream #1:
  
    keyframe=1
  
  1512775956026 - stderr:   duration=0.000
  
    dts=N/A  pts=N/A
  
    size=992
  
  [hls @ 0x7f81fd80f000] Timestamps are unset in a packet for stream 1. This is deprecated and will stop working in the future. Fix your code to set the timestamps properly
  
  1512775956026 - stderr: stream #0:
  
    keyframe=1
  
    duration=0.000
  
  1512775956026 - stderr:   dts=0.180  pts=0.180
  
    size=108
  
  1512775956027 - stderr: stream #1:
  
    keyframe=0
  
    duration=0.000
  
  1512775956027 - stderr:   dts=0.002  pts=0.002
  
    size=3047
  
  [hls @ 0x7f81fd80f000] pkt->duration = 0, maybe the hls segment duration will not precise
  
  stream #0:
  
    keyframe=1
  
    duration=0.000
  
    dts=0.200  pts=0.200
  
    size=89
  
  1512775956060 - stderr: stream #0:
  
    keyframe=1
  
    duration=0.000
  
    dts=0.220  pts=0.220
  
    size=73
  
  stream #0:
  
    keyframe=1
  
    duration=0.000
  
    dts=0.240  pts=0.240
  
    size=78
  
  stream #0:
  
    keyframe=1
  
    duration=0.000
  
    dts=0.260  pts=0.260

  Notice how the first frame for stream #1 (video) starts after a number of audio frames ? Specifically, it starts at stream #0 dts/pts 0.18. In this situation, the a/v sync issue is pretty much unnoticeable, but with a bunch of repros, I’ve determined that the a/v sync offset is always the duration of however long audio frames were sent before the first video frame (sometimes seconds). I’m consistently starting the RTP streams only tens of ms apart, so I can’t control for this variance on the input side.

  After the initial audio frames come in, the first video frame has a dts/pts around 0. What ffmpeg setting would I use to adjust the timestamps accordingly ? I don’t care about losing the starting audio that doesn’t have video, so any solution that would adjust the timestamps works.

• How to measure the performance of a newsletter (or any email) with Piwik

  19 décembre 2017, par InnoCraft — Community

  To be able to grow your business, it is crucial to track all your marketing efforts. This includes all newsletters and emails that you share with people outside of your business. Otherwise, you won’t be able to know which of your daily efforts are yielding results.

  Are you wondering if it is possible to track the performance of an emailing campaign in Piwik efficiently ? Would you like to know if it is technically easy ? No worries, here is a “How to” tutorial showing you how easily you can track an emailing in Piwik properly.

  Different tracking levels for different needs

  There are many things that you may be interested to track, for example :

  

  1. How many users opened your email
  2. How many users interacted with the links in your email
  3. How many users interacted on your website through your email

  Let’s have a look at each of these levels.

  Step 1 – Tracking email and newsletter openings in Piwik

  Tracking email openings requires to add an HTML code to your newsletter. It works through what we call a tracking pixel, a tiny image of 1×1 that is transparent so the user will not be able to see it.
  In order to install it, here is an example of what this code looks like :

  <img src="https://piwik.example.com/piwik.php?idsite=YOUR_PIWIK_WEBSITE_ID&rec=1&bots=1&url=https%3A%2F%2Fexample.com%2Femail-opened%2Fnewsletter_XYZ&action_name=Email%20opened&_rcn=internal%20email%20name&_rck=newsletter_XYZ" style="border:0;” alt="" />

  The Piwik tracking pixel explained

  The above URL is composed of the following URL parameters which are part of our Tracking API :

  • idsite : Corresponds to the ID of the website you would like to track.
  • rec : You need to have rec=1 in order for the request to be actually recorded.
  • bots : Set it to 1 to include all the connections made to this request, bots included.
  • url : corresponds to the URL you would like to display in Piwik every time the email is opened.
  • action_name : This is the page name you would like to be tracked when the email is opened.
  • _rcn : The name you would like to give to your campaign.
  • _rck : The keyword you may like to use in order to summarize the content of your newsletter.

  You may have noticed some special characters here such as “%20”, “%2F”. That’s because the URL is encoded. We strongly recommend you to do so in order for your tracking not to break. Many tools are available on the web in order to encode your URLs such as https://www.urlencoder.org/.

  If you would like to access the previous tracking code easily, keep in mind that you can always find the tracking code generator within the “Piwik admin panel → Tracking code” :

  

  You can find more information about it on our guide at : How do I track how many users open and read my newsletter emails (using a pixel / beacon) ?

  As a result, the information will be pushed as following for any user who opens your email :

  

  To not bias your regular page views on your website with newsletter openings, we recommend tracking newsletter openings into a new website.

  Tracking even more data : the user ID example

  You can go deeper in your URL tracking by inserting other parameters such as the user id if you have this information within your emailing database. One of the main benefit of tracking the User ID is to connect data across multiple devices and browsers for a given user.

  You only need to add the following parameter &uid=XXX where XXX equals the dynamic value of the user ID :

  

  Make sure that UID from your emailing provider is the same as the one used on your website in order for your data to be consistent.

  Important note : some email providers are loading email messages by default which results in an opening even if the user did not actually open the email.

  Step 2 – Measure the clicks within your emailing

  Tracking clicks within an email lets you know with which content readers interacted the most. We recommend tracking all links in all your emails as a campaign, whether it is a newsletter, a custom support email, an email invoice, etc. You might be surprised to see which of your emails lead to conversions and if they don’t, try to tweak those emails, so they might in the future.

  Tracking clicks This works thanks to URL campaign tracking. In order to perform this action, you will need to add Piwik URL parameters to all your existing link URLs :

  • Website URL : for example “www.your-website.com”.
  • Campaign name : for example “pk_campaign=emailing”. Represents the name you would like to give to your campaign.
  • Campaign keyword : for example “pk_keyword=name-of-your-article”. Represents the name you would like to give to your content.
  • Campaign source : for example “pk_source=newsletter”. Represents the name of the referrer.
  • Campaign medium : for example “pk_medium=email”. Represents the type of referrer you are using.
  • Campaign content : for example “pk_content=title”. Represents the type of content.

  You can find more information about campaign url tracking in our “Tracking marketing campaigns with Piwik” guide.

  Here is a sample showing you how you can differentiate some links in a newsletter, all pointing to the same URL :

  

  Once you have added these URL parameters to each of your link, Piwik will clearly indicate the referrer of this specific campaign when a user clicks on a link in the newsletter and visits your website.

  Important note : if you do not track your campaigns, it will result in a bad interpretation of your data within Piwik as you will get webmail services or direct entries as referrer instead of your newsletter campaign.

  Step 3 – Measure emailing performances on your website

  Thanks to Piwik URL campaign parameters, you can now clearly identify the traffic brought through your emailing. You can now specifically isolate users who come from emails by creating a segment :

  

  Once done, you can either have a look at each user specifically through the visitor log report or analyze it as a whole within the rest of the reports.

  You can even measure your return on investment directly if goals have been defined. In order to know more about how to track goals within Piwik.

  Did you like this article ?

  If you enjoyed reading this article, do not hesitate to share it around you. Moreover, if there are any topics you would like to write us about in particular, just drop us an email and we will be more than happy to write about it.