This document discusses generating multiple still images from videos in MediaMosa. It describes how to generate different types of stills (normal, second, scene) from a mediafile using REST calls. It also covers uploading stills and working with multiple stills by ordering, setting the default, and deleting stills.

1. MULTIPLE STILL GENERATION IN MEDIAMOSA Peter Forgacs, Madcap English presentation

2. Introduction Who am I? Software developer at Madcap A developer of MediaMosa Hobby: Internet, Music, Game development

3. Introduction: MediaMosa Connection between assets and videos.

4. Introduction: MediaMosa Asset is a container. Asset

5. Introduction: MediaMosa Asset may have title, description etc. Asset Title Description DC, QDC fields

6. Introduction: MediaMosa Asset may have mediafiles. Asset Title Description Mediafile

7. Introduction: MediaMosa A mediafile may have a video. Asset Title Description Mediafile: Video (codec, filesize)

8. Introduction: MediaMosa We can transcode a mediafile to an other format. Asset Title Description Mediafile: Video (Original) Mediafile: Video (Transcoded)

9. Introduction: MediaMosa We can create an another mediafile (with video). Asset Title Description Mediafile: Video (Original) Mediafile: Video (Transcoded) Mediafile: Video (Original)

10. Introduction: MediaMosa Every mediafile may have still images. Asset Title Description Mediafile: Video (Original) Mediafile: Video (Transcoded) Mediafile: Video (Original)

11. Introduction: MediaMosa The asset has a default still (if there is any). Asset Title Description Mediafile: Video (Original) Mediafile: Video (Transcoded) Mediafile: Video (Original)

12. Introduction: MediaMosa A video sites has assets with default stills. Asset Title Desc. Asset Title Desc. Asset Title Desc. Asset Title Desc.

13. Introduction: MediaMosa A video page has an asset with video(s) and still(s). Asset Title Description

14. Main points Generate still Generate multiple stills Upload still Working with multiple stills

15. Introduction WLE WLE (White Label Ega) is a client side application for testing. We will use this software in this presentation.

16. A word without still images

17. A video without still images

18. People without faces The still images are the face of the videos.

19. Still type NONE

20. Still type NONE

21. REST interface, REST calls The REST interface is a communication channel between the client application and the MediaMosa. A REST call request can be GET or POST (PUT). - GET is for getting data from MediaMosa. - POST (PUT) is for changing data (eg. file upload). The response is an XML about the status and the data.

22. WLE REST interface

23. MediaMosa.org API page REST call: Parameters, Response fields, Examples http://mediamosa.org/api

24. MediaMosa.org API page REST call: Parameters, Response fields, Examples http://mediamosa.org/api

25. Still type NONE REST call mediafile/$mediafile_id/still/create POST: still_type=NONE (This is the default value)

26. Black still? Is it possible?

27. Black still? Is it possible? No, it isn't.

28. Black still? MediaMosa try to avoid unicolor (black, white, pink ...) images.

29. Black still - NO!

30. Multiple stills One still good, multiple stills are better. Types - Normal (creating N stills from a video) - Second (creating stills in every N second) - Scene (creating stills, when the video has a scene change)

31. Still type NORMAL mediamosa/$mediafile_id/still/create [POST] still_type=NORMAL&still_per_mediafile=3

32. Black still check?

33. Black still check? Just for still type NONE.

34. Still type SECOND mediamosa/$mediafile_id/still/create still_type=SECOND&still_every_second=5

35. Padding Still default size, padding (YES, NO). still_type=NONE&h_padding=0&v_padding=15&size=352x288

36. Scene stills Create stills on the video scene changes. Requirements: - Patch ffmpeg (NORMAL, SCENE too) - lav2yuv: * Part of MJPEG Tools * apt-get install mjpegtools * MediaMosa status page

37. Still type SCENE mediamosa/$mediafile_id/still/create still_type=SCENE

38. I, robot It is not easy to decide what is a scene change. The computer is not human. Is it a perfect tool? No, it doesn't. Accuracy ~70%. With our fixes ~80%. It is useful, if we know the advantages and disadvantages of scene stills.

39. Still type SCENE result

40. Uploading still images asset/$asset_id/still/upload mediafile_id=$mediafile_id

41. Uploading still result

42. Working with multiple stills Ordering Make default Delete

43. Ordering stills asset/$asset_id/still/order mediafile_id=$mediafile_id &still_id=$still_id &order=-3

44. Ordering stills

45. Make still as default asset/$asset_id/still/default mediafile_id=$mediafile_id &still_id=$still_id

46. Make still as default

47. Delete still Deleting from asset, from mediafile, or delete a unique still asset/$asset_id/still/delete POST: <nothing> or mediafile_id or still_id

48. Delete still

49. FFmpeg tricks Creating multiple stills without using MediaMosa (and without patching ffmpeg). For extracting images from a video: ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg This will extract one video frame per second from the video and will output them in files named foo-001.jpeg, foo-002.jpeg, etc. Images will be rescaled to fit the new WxH values.

50. Summary Generate still Generate multiple stills * Normal * Second * Scene Upload still Working with multiple stills * Order * Set default * Delete

51. Videos with stills

52. Videos with stills

56. Questions? Thank you! Peter Forgacs [email_address]