Re: [FFmpeg-user] essence MD5 for still images
2018-01-09 22:25 GMT+01:00 ***: > On the same subject Appears to be a different subject, but most of all, please remember not to top-post on this mailing list. > when calculating the MD5 of an audio WAV file ffmpeg > defaults to 16 bit. No, ffmpeg does not default to "16 bit" or a particular encoder, some muxers default to pcm_s16le for audio if you do not specify a particular encoder. > If the input is 24 bit it is my understanding that > it needs to be explicitly reflected in the command > as -c:a pcm_s24le otherwise the resulting MD5 will > not be accurate. So, yes, if you need accurate md5 for 24 bit input, you have to specify a 24 bit encoder. > Are there comparable variations in the way ffmpeg > processes still image files of different formats, bit > depths, etc., that need to be accounted for in the > command that is used? Typically not: The rawvideo (and the wrapped_avframe) encoder accepts any pix_fmt while the pcm_s16le encoder only accepts s16 input, the pcm_s24le encoder only supports s32 (sic!). Carl Eugen ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] essence MD5 for still images
On the same subject, when calculating the MD5 of an audio WAV file ffmpeg defaults to 16 bit. If the input is 24 bit it is my understanding that it needs to be explicitly reflected in the command as -c:a pcm_s24le otherwise the resulting MD5 will not be accurate. Are there comparable variations in the way ffmpeg processes still image files of different formats, bit depths, etc., that need to be accounted for in the command that is used? On Sat, Jan 6, 2018 at 4:31 PM, Carl Eugen Hoyoswrote: > 2018-01-06 20:38 GMT+01:00 *** : > > > Somewhere I discovered that ffmpeg will create essence > > MD5s for supported still image formats. > > And audio and video. > (From FFmpeg's pov, an image format is a video format.) > > > I began using the following command to verify that > > the image essence did not change in photos after > > their IPTC metadata is revised. > > > Because there is no documentation of such a use case > > on the ffmpeg site nor anywhere else on the web I have > > begun to doubt that this is a valid use of ffmpeg or this > > command. > > Different possibilities exist within FFmpeg to calculate > checksums, the FFmpeg regression tests are a usage > example. > > > Is anyone else doing this? > > Many people are. > > > Even if you aren’t I would appreciate any comments or > > observations that you care to share. > > > > ffmpeg -i INPUT -map 0:v -f md5 OUTPUT.md5 > > This command line will calculate the md5sum of the first > video stream in the input file. > You may want to look at the framemd5 muxer for other > use-cases, other algorithms also exist. > > Carl Eugen > ___ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] essence MD5 for still images
2018-01-06 20:38 GMT+01:00 ***: > Somewhere I discovered that ffmpeg will create essence > MD5s for supported still image formats. And audio and video. (From FFmpeg's pov, an image format is a video format.) > I began using the following command to verify that > the image essence did not change in photos after > their IPTC metadata is revised. > Because there is no documentation of such a use case > on the ffmpeg site nor anywhere else on the web I have > begun to doubt that this is a valid use of ffmpeg or this > command. Different possibilities exist within FFmpeg to calculate checksums, the FFmpeg regression tests are a usage example. > Is anyone else doing this? Many people are. > Even if you aren’t I would appreciate any comments or > observations that you care to share. > > ffmpeg -i INPUT -map 0:v -f md5 OUTPUT.md5 This command line will calculate the md5sum of the first video stream in the input file. You may want to look at the framemd5 muxer for other use-cases, other algorithms also exist. Carl Eugen ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
[FFmpeg-user] essence MD5 for still images
Hello Somewhere I discovered that ffmpeg will create essence MD5s for supported still image formats. I began using the following command to verify that the image essence did not change in photos after their IPTC metadata is revised. Because there is no documentation of such a use case on the ffmpeg site nor anywhere else on the web I have begun to doubt that this is a valid use of ffmpeg or this command. Is anyone else doing this? Even if you aren’t I would appreciate any comments or observations that you care to share. ffmpeg -i INPUT -map 0:v -f md5 OUTPUT.md5 Thank you Kevin Irelan ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] essence MD5
ganesh.ire...@syda.org wrote: >ffmpeg -i "INPUT" -map 0:a -f md5 -hash md5 - Add "-loglevel quiet". ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] essence MD5
2016-10-12 14:16 GMT+02:00: > I want to generate an essence MD5 for WAV files and then > populate that value into a field in a DAM system. Just curious: What is a DAM system? > I have tested two commands to generate the essence MD5 > hash. > > ffmpeg -i INPUT -map 0:a -f md5 OUTPUT.md5 > ffmpeg -i "INPUT" -map 0:a -f md5 -hash md5 - > > Neither of these is ideal. The first one puts the value in a > separate file. (That's what you asked for) > The second puts it amongst other info in the console making > it difficult to parse out as in the following example. Only one line is printed to stdout. An alternative is to use -loglevel warning or error or fatal. > This e-mail (including any attachments) is intended only for > use by the addressee(s) named herein and may contain > legally privileged and/or confidential information. Please avoid this when sending emails to a public mailing list. Carl Eugen ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
[FFmpeg-user] essence MD5
Hello, Non-developer here... I want to generate an essence MD5 for WAV files and then populate that value into a field in a DAM system. I have tested two commands to generate the essence MD5 hash. ffmpeg -i INPUT -map 0:a -f md5 OUTPUT.md5 ffmpeg -i "INPUT" -map 0:a -f md5 -hash md5 - Neither of these is ideal. The first one puts the value in a separate file. The second puts it amongst other info in the console making it difficult to parse out as in the following example. (The value I want is the fourth line from the bottom.) Is there an FFMPEG command that will give a cleaner console output than this? Thank you, Kevin C:\>ffmpeg -i "Test BWAV 2.wav" -map 0:a -f md5 -hash md5 - ffmpeg version N-79546-g13406b6 Copyright (c) 2000-2016 the FFmp built with gcc 5.3.0 (GCC) configuration: --enable-gpl --enable-version3 --disable-w32thr isynth --enable-bzlib --enable-fontconfig --enable-frei0r --enab le-iconv --enable-libass --enable-libbluray --enable-libbs2b --e enable-libfreetype --enable-libgme --enable-libgsm --enable-libi modplug --enable-libmfx --enable-libmp3lame --enable-libopencore libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable e-libschroedinger --enable-libsnappy --enable-libsoxr --enable-l -libtheora --enable-libtwolame --enable-libvidstab --enable-libv ble-libvorbis --enable-libvpx --enable-libwavpack --enable-libwe 264 --enable-libx265 --enable-libxavs --enable-libxvid --enable- -lzma --enable-decklink --enable-zlib libavutil 55. 22.100 / 55. 22.100 libavcodec 57. 35.100 / 57. 35.100 libavformat57. 34.102 / 57. 34.102 libavdevice57. 0.101 / 57. 0.101 libavfilter 6. 44.100 / 6. 44.100 libswscale 4. 1.100 / 4. 1.100 libswresample 2. 0.101 / 2. 0.101 libpostproc54. 0.100 / 54. 0.100 Guessed Channel Layout for Input Stream #0.0 : stereo Input #0, wav, from 'Test BWAV 2.wav': Metadata: comment : Test File with BEXT time_reference : 0 Duration: 00:00:14.55, bitrate: 1413 kb/s Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 s16, 1411 kb/s [md5 @ 00506520] Using AVStream.codec to pass codec para is deprecated, use AVStream.codecpar instead. Output #0, md5, to 'pipe:': Metadata: comment : Test File with BEXT time_reference : 0 encoder : Lavf57.34.102 Stream #0:0: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 k Metadata: encoder : Lavc57.35.100 pcm_s16le Stream mapping: Stream #0:0 -> #0:0 (pcm_s16le (native) -> pcm_s16le (native)) Press [q] to stop, [?] for help MD5=0c9f578c5d4849d4f18e07dfe08370e5 size= 0kB time=00:00:14.55 bitrate= 0.0kbits/s speed= 93 video:0kB audio:2507kB subtitle:0kB other streams:0kB global hea overhead: unknown This e-mail (including any attachments) is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail, you are notified that any dissemination, distribution or copying of it (including any attachments), or taking any actions based on it, is prohibited. If you have received this e-mail in error, please immediately notify the sender by reply e-mail, delete the original, and destroy any copies or printouts. Thank you. em-tr-v1-2016 ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".