I am trying to write subtitles and display them at lots of positions throughout a video at arbitrary positions. I have a long list of times and positions to display the text in the video, but I don't know how to encode these times and positions into the subtitles file. A lot of the examples on the web only show how to display a single subtitle, or don't explain the syntax of the subtitles files.
I couldn't find a simple answer to how to do this, so I had to put together a lot of methods, and I'm going to answer my own question.
The main options for doing this are:
Using a GUI/standalone program (#llogan mentioned aegisub)
'drawtext' filter in ffmpeg
subtitles filter with an SRT file
subtitles filter with an SSA file
subtitles filter with an ASS file
I wanted to write my own subtitles in a text file (to make it scriptable), not use a standalone GUI. Some of methods don't allow arbitrary positioning (the subtitle will always be centered at the bottom). Others don't allow loading a long list of subtitles from a file, ie you have to encode them all into the ffmpeg command string, which is unwieldy.
Here's the documentation on the subtitles filter, but it doesn't actually explain the syntax of the accompanying files. In fact I found it very difficult to find clear documentation of ANY of the options for subtitles files. I went with ASS because it seemed to work, and I discovered enough templates on the internet that I was able to figure out the most important features by trial and error.
First, create a text file called desc.ass that looks like this:
[Script Info]
PlayResY: 600
WrapStyle: 1
[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, Alignment, MarginL, MarginV
Style: N,Arial,60,&H00FFFF,1,425,550
Style: NE,Arial,60,&H00FFFF,1,650,480
Style: E,Arial,60,&H00FFFF,1,700,250
Style: SE,Arial,60,&H00FFFF,1,600,50
Style: S,Arial,60,&H00FFFF,1,400,0
Style: SW,Arial,60,&H00FFFF,1,150,50
Style: W,Arial,60,&H00FFFF,1,100,250
Style: NW,Arial,60,&H00FFFF,1,150,500
[Events]
Format: Start, End, Style, Text
Dialogue: 00:00:01.00, 00:00:05.00, E, Text to display with the E style
Dialogue: 00:00:05.00, 00:00:05.50, N, Text to display with the N style
The actual file has many many more "Dialogue" lines after this, but I truncated for readability.
I don't really understand the Script Info section yet. :(
The V4+ Styles section allows you to specify an arbitrary number of "Styles", which define color, position, font, and a lot of other things. Each actual subtitle will use one of these styles.
If you have a small number of positions that each subtitle will be displayed in, I think it's easier to define a Style for each position. Because I wanted to display subtitles at one of 8 positions, I defined 8 styles. But you can override the position of any given subtitle (see below). So another option is to use a single Style for everything, and just define the position of each subtitle as necessary.
PrimaryColour is a hex color argument (although it seems to be backwards for some reason, so yellow gives you cyan and vice versa).
Alignment refers to the numerical keypad, so 1 means lower left and 5 means center.
MarginL and MarginV allow you to apply horizontal and vertical offsets to the default alignment.
You can specify lots more attributes here just by adding elements to the Format line, and then specifying them on each Style line. This page is the most comprehensive documentation I could find.
Everybody on the internet copy/pastes the same example text with lots of formats specified (e.g., here). This is another, simpler example. Would be great if someone could post clear documentation on what each of these attributes mean!
The [Events] section defines the individual subtitles. Here, I'm only specifying the basics: start time, end time, style name, and the text.
You can override the position of any given Dialogue element by adding the string {\pos(400,570)} to the beginning of the Text element on that line. (Obviously replace 400, 570 with your desired position.)
You can preview the results of applying these subtitles to a video named video.mkv with ffplay like this:
ffplay -i video.mkv -vf "subtitles=desc.ass"
Some people call this soft-subbing because the video itself isn't being changed, the subtitles are just displayed over it.
If you want to burn the subtitles permanently into the video (sometimes called hard-subbing), you can re-encode like this:
ffmpeg -i video.mkv -vf "subtitles=desc.ass" video_with_subtitles.mkv
Ref for burning subtitles
we use the Windows Media Player plugin to play some video pages on firefox 20. This works great, but after a while (this differs, but often after round about 30 minutes) the videos will be not longer shown and instead of the video only a small horiziontal green line in the middle of the video area is shown (on black background). The video files are ok because the same files will be played successfull before the green line is shown. And after restarting firefox all is still fine until after several minutes the green line is shown again ...
I have already installed the latest graphic driver. Also dis-/enabling Video Acceleration in Windows Media Player don't helps.
Here our environment:
Win7 64b
WMP 12.0.7601.17514
Firefox 20.0.1
Windows Media Player Firefox Plugin 1.0.0.8
EDIT:
I can see that the Media Player creates for each played video a own playlist. In the status bar of the WMP plugin stands "Wiedergabeliste1", Wiedergabeliste2", "Wiedergabeliste3", ... ("Wiedergabeliste" means "playlist") for the first, second, third, ... video. But with the first video which is displayed as a green line on the status bar stands only the name of the video file (without ".wmv").
Also if the videos are showing correct the "Statistic" (right mouse click into the WMP plugin) shows me valid values for frame rate and so on. But if only the green line was shown the frame rate and some other values are "0".
I have also tested this with Firefox 22 with the same effect (green line after some minutes). On IE 8 the effect is a little bit different. After some minutes I get then green line too, but only for each second video (one video is ok, next video a green line, next video ok again, next video a green line , ...)
Thanks and regards,
Steffen
PS: This is also posted on: http://answers.microsoft.com/en-us/windows/forum/windows_7-pictures/windows-media-player-small-green-horizontal-line/c9ea0621-a678-4017-9aac-55a1239db632
Seems this problem is related to the Hardware. We have found out that the green line occurres only on one Hardware and on at least three other Hardware machines not. But it seems it's not related to the graphic card (Intel/ATI HD4000) because we have not seen this problem on a other machine with the same CPU and graphic card ...
I have an Autocad drawing which is a plan for land squares where each square contains a number.
I tried to convert it to image by choosing: File --> Export Data --> and file format Bitmap (bmp). (I have Autocad 2013 Mac version)
the file converted to image, but the quality is too bad, I can't see the land numbers inside the square when I zoom in the image.
I tried also with Postscript (PS file format), quality is a bit better but it's still bad.
Is there away to convert Autocad file to image but still preserve it's high quality details
I need to convert the file to image because I would like to publish it online on my website. maybe there other was to publish autocad file on line, if so, please advice. But the trick I want the background of the autcad (plan) to be transparent so that I could display it on top of Google maps. I if I used autocad plugin I can't make it transparent. right?
Use the PLOT (for the current drawing) or PUBLISH (for batching) commands to produce high quality images.
I have an issue with a image file on XP and windows 7 but it works perfectly in windows 2008 box. Coming to the actual issue, the TIF image in the question is a Invoice form image with a white background with Invoice details. When I open it in 2008 it opens with white background but when I open it in XP and Windows 2008, it turns to black background with white color text. I am seeking some help on this issue.
1. Is it a OS issue
2. if it is a OS issue, how do I change the background color to white using any code preferably C# as I am using C# for developemnt.
Thanks in advance
Satish
Simply we can interchange the Palettes then Issue will be resolved by this...
Dim plet As ColorPalette = Image.Palette
plet.Entries(1) = c1
plet.Entries(0) = c2
Image.Palette = plet
But struck at identifying the Images that are having problem, i.e. because we have to apply this to the Images that are having Issues only. Otherwise correct images also inverted.
Could be a CMYK or transparency issue, or that it's saved in 16-bit color format (per component).
But this is hard to determine without access to one actual file for analysis.
Update:
Problem 1: For TIFF files - on Windows XP the Photometric tag is ignored by Windows Photo viewer and its underlying technology, with TIFF files using a single bitplane (2 colors). This is a bug.
Solution 1a: Manually enter (switching for existing) palette entries to force bit 0 (off) black and bit 1 (on) white.
Solution 1b: Save files as RGB files /gray-scale would be more ideal, but in GDI+ there is no good support for 8-bit gray-scale files IMO).
Problem 2: Byte-order. On Windows XP, the byte-order (big-endian) can cause problems. Normally TIFFs are saved in Motorola big-endian format (MSB) but on Windows XP the TIFF file is assumed to be in little-endian format.
Solution 2a: Save new TIFF files with little-endian order (Intel) for new files
Solution 2b: If Re-saving (re-scanning) is not an option for existing files, re-order content for existing files switching byte-order from LSF (Intel) to MSF (Motorola). Update header to indicate new byte-order (replace II for MM etc.).
I downloaded a explosion generator that makes an animated explosion but saves each frame as a seperate png image. I cant for the life of me find a tool that will take all the images and make an animated strip image, with the frames next to each other. I tried gimp but no luck! The Photoshop image combiner is too cumbersome. Any recommended utilites to do this?
Gimp can do this, and it is actually a piece of cake.
Open all the frames as individual images. Then on the first image select Filters|Combine|Film Strip. Add the remaining frames to the list on the right side (in the correct order).
Now click on the Advanced tab and set Image Height all the way to the right (1.000) and Image spacing all the way to the left (0.000).
Hit OK and you should have your filmstrip!
The GIMP film strip works fine but does force a background color on you, if you have images with transparent (alpha) background this might be problematic for you.