Develop Reference

Buffered Writer occasionally creates symbols rather than numbers

So I have a program that collects a bunch of data and continuously concatenates the data into a string with a single white space between each entry. During my close routine I print the String into a txt file using buffered writer. About 50% of the time the data shows up as (mostly) Chinese symbols. Is the VM doing some weird Unicode stuff? Why does this only occur sometimes?
I've looked around on other forums and have not seen other instances of this problem. None of the other CS majors I know understand what is happening.
EDIT : the data is all integer numbers ranging 0-1365;
UPDATE: upon further research I found this which makes me think a may need a PrintStream rather than a BufferedWriter can anyone speak to that? I tested the PrintStream and I will not be able to construct it with a FileWriter as I would a BufferedWriter which means I need more research to write to my txt.
UPDATE: printing to the console does not make this error occur. I will accept an answer that explains way Notepad (the program I am using to open the txt) sometimes displays numbers and sometimes displays symbols.
Here is the relevant code:
//fields
private static BufferedWriter out;
private File saveFile;
String data;
//inside constructor
this.saveFile = new File("C:\\Users\\HPlaptop\\Desktop\\MouseData.txt");
this.saveFile.delete();
try{this.saveFile.createNewFile();}
catch (IOException e ){System.out.println("File creation error");}
try {out = new BufferedWriter(new FileWriter("C:\\Users\\HPlaptop\\Desktop\\MouseData.txt"));}
catch (IOException e) {System.out.println("IO Error");}
this.control.addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{ //there is a method call here but the basics are below
out.write(data);
out.close();
System.exit(0);
}
});
Here is an example data set printed correctly:
1365 767 1365 767 1365 767 1364 767 1353 756 1268 692 1114 604 980 488 812 334 744 283 694 244 593 150 473 81 328 13 207 0 124 0 115 0 102 0 99 6 107 13 132 20 173 32 187 31 190 25 194 20 201 17 215 14 221 10 224 7 224 7 224 7 226 6 226 6 226 6 226 6 226 6 226 6 226 6
This data set was taken seconds later and is not what I want
㐀ㄹ㈠㤰㐠㔸㈠㈱㐠㠶㈠㐱㐠㘲㈠㘰㌠㠷ㄠ㔹㌠㌳ㄠ㌹㈠㘹㈠㄰㈠㠷㈠㜳㈠㐶㈠㐷㈠㐶㈠㔷㈠㌶㈠㔵㈠㐵㈠㠰㈠㤴ㄠ㔲㈠㤴㐠‶㐲‹㌱㈠㘴〠㈠㘴〠㈠㘴〠㈠㜴〠㈠㠴〠㈠㠴〠㈠㜴㠠㈠㔴ㄠ‶㐲‵㤱㈠㔴ㄠ‹㐲‵㠱㈠㜴ㄠ‶㐲‹ㄱ㈠〵ㄠ‰㔲‰〱

The BufferedWriter is not making an error and the code is correct except for
the redundancy of using
this.saveFile.delete();
try{this.saveFile.createNewFile();}
catch (IOException e ){System.out.println("File creation error");}
and
new FileWriter
The error in reading the data occurs when the file is opened. The depending on what program opens the data different results are displayed because of the way the software reads the data. Notepad was displaying symbols because it interpreted the numbers as ASCII. The console did not try to interpret the data and just displayed what was written to it. Using a program that does not try to interpret the numbers in the file will allow the data to be viewed correctly.

Since you did not provide and example of what data you write into the stream, you are probably experiencing the bush hid the facts phenomenon.

Using FFMPEG Android Library to convert PCM to m4a [duplicate]

I am using ffmpeg to convert videos to mp4 format. Everything works fine except with MOV format.
The command I use for everything is:
ffmpeg -i input.mov -strict experimental -sameq -s vga -aspect 1.7777 -vcodec libx264 -preset fast -crf 22 -y output.mp4
but the output I keep getting is:
ffmpeg version 0.9, Copyright (c) 2000-2011 the FFmpeg developers
built on Mar 12 2012 11:01:05 with gcc 4.4.5
configuration: --enable-libx264 --enable-gpl --disable-yasm
libavutil 51. 32. 0 / 51. 32. 0
libavcodec 53. 42. 0 / 53. 42. 0
libavformat 53. 24. 0 / 53. 24. 0
libavdevice 53. 4. 0 / 53. 4. 0
libavfilter 2. 53. 0 / 2. 53. 0
libswscale 2. 1. 0 / 2. 1. 0
libpostproc 51. 2. 0 / 51. 2. 0
[mov,mp4,m4a,3gp,3g2,mj2 # 0x21767a0] Referenced QT chapter track not found
Seems stream 0 codec frame rate differs from container frame rate: 30.00 (30/1) -> 30.07 (2225/74)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mov':
Metadata:
creation_time : 2009-04-04 07:12:29
comment : EASTMAN KODAK COMPANY KODAK Z1275 ZOOM DIGITAL CAMERA
comment-eng : EASTMAN KODAK COMPANY KODAK Z1275 ZOOM DIGITAL CAMERA
Duration: 00:00:17.76, start: 0.000000, bitrate: 8100 kb/s
Stream #0:0(eng): Video: mpeg4 (Advanced Simple Profile) (mp4v / 0x7634706D), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 7968 kb/s, 30.07 fps, 30.07 tbr, 8544k tbn, 30 tbc
Metadata:
creation_time : 2009-04-04 07:12:29
handler_name :
Stream #0:1(eng): Audio: pcm_mulaw (ulaw / 0x77616C75), 16000 Hz, 1 channels, s16, 128 kb/s
Metadata:
creation_time : 2009-04-04 07:12:29
handler_name :
[buffer # 0x2187f00] w:1280 h:720 pixfmt:yuv420p tb:1/1000000 sar:1/1 sws_param:
[scale # 0x219c120] w:1280 h:720 fmt:yuv420p -> w:640 h:480 fmt:yuv420p flags:0x4
[libx264 # 0x2190d20] using SAR=4/3
[libx264 # 0x2190d20] using cpu capabilities: none!
[libx264 # 0x2190d20] profile High, level 3.0
[libx264 # 0x2190d20] 264 - core 120 - H.264/MPEG-4 AVC codec - Copyleft 2003-2012 - http://www.videolan.org/x264.html - options: cabac=1 ref=2 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=6 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=12 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=1 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=30 rc=crf mbtree=1 crf=22.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
[aac # 0x21917e0] Too many bits per frame requested
Output #0, mp4, to 'output.mp4':
Metadata:
creation_time : 2009-04-04 07:12:29
comment : EASTMAN KODAK COMPANY KODAK Z1275 ZOOM DIGITAL CAMERA
comment-eng : EASTMAN KODAK COMPANY KODAK Z1275 ZOOM DIGITAL CAMERA
Stream #0:0(eng): Video: h264, yuv420p, 640x480 [SAR 4:3 DAR 16:9], q=-1--1, 90k tbn, 30.07 tbc
Metadata:
creation_time : 2009-04-04 07:12:29
handler_name :
Stream #0:1(eng): Audio: aac, 16000 Hz, 1 channels, s16, 128 kb/s
Metadata:
creation_time : 2009-04-04 07:12:29
handler_name :
Stream mapping:
Stream #0:0 -> #0:0 (mpeg4 -> libx264)
Stream #0:1 -> #0:1 (pcm_mulaw -> aac)
Error while opening encoder for output stream #0:1 - maybe incorrect parameters such as bit_rate, rate, width or height
It seems the problem is with audio's bit per frame.
Which might be the right solution?

The "Too many bits per frame requested" error is coming from the native FFmpeg AAC encoder (-c:a aac). You can use one or more of the following solutions:
Update your ffmpeg
Development is very active and the native FFmpeg AAC encoder has seen many improvements; it will now automatically clamp to the max number of bits per frame instead of failing with this error. See the FFmpeg Download page for links to already compiled binaries which are the easiest method to get a recent ffmpeg.
If you're stuck with an old, outdated, ancient ffmpeg:
Increase the audio sampling rate such as by adding -ar 44100.
Decrease your bitrate. Default is probably -b:a 128k. Try lower values until it works.
Use -c:a copy to stream copy (re-mux) the audio, and, because MP4 doesn't support pcm_mulaw, use different output container format such as Matroska (.mkv).
Use a different AAC encoder such as libfdk_aac if your ffmpeg supports it.
You don't need to do any of these options if you upgrade ffmpeg.

I'd hope ffmpeg is more clever than this, but you might try specifying the video stream for your -s and -aspect options: -s:v and -aspect:v.
Alternately, since you're not doing anything special with the audio, you could copy it explicitly with -c:a copy.

Setting video stream metadata using Ffmpeg

I'm using the JavaCV FFmpegFrameRecorder class to encode Android's camera preview frames into a video.
The goal would be to replicate the result of the following command line:
ffmpeg -i input.mp4 -metadata:s:v:0 rotate="90" output.mp4
I modified the startUnsafe() method as follows, but it failed to generate the desired output:
if ((video_st = avformat_new_stream(oc, video_codec)) != null) {
video_c = video_st.codec();
video_c.codec_id(oformat.video_codec());
video_c.codec_type(AVMEDIA_TYPE_VIDEO);
...
AVDictionary avDictionary = new AVDictionary(null);
av_dict_set(avDictionary, "rotate", "90", 0);
video_st.metadata(avDictionaty);
...
}
...
avformat_write_header(oc, (PointerPointer) null);
This still encodes the video correctly, but the added metadata never appears on ffprobe. If it helps, the video encoding is h264.
By the way, here's the ffprobe output:
ffprobe version 2.3.3 Copyright (c) 2007-2014 the FFmpeg developers
built on Jan 22 2015 18:22:57 with Apple LLVM version 6.0 (clang-600.0.56) (based on LLVM 3.5svn)
configuration: --prefix=/usr/local/Cellar/ffmpeg/2.3.3 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-nonfree --enable-hardcoded-tables --enable-avresample --enable-vda --cc=clang --host-cflags= --host-ldflags= --enable-libx264 --enable-libfaac --enable-libmp3lame --enable-libxvid --enable-libfreetype --enable-libvorbis --enable-libvpx --enable-libass --enable-ffplay --enable-libfdk-aac --enable-libopus --enable-libquvi --enable-libx265
libavutil 52. 92.100 / 52. 92.100
libavcodec 55. 69.100 / 55. 69.100
libavformat 55. 48.100 / 55. 48.100
libavdevice 55. 13.102 / 55. 13.102
libavfilter 4. 11.100 / 4. 11.100
libavresample 1. 3. 0 / 1. 3. 0
libswscale 2. 6.100 / 2. 6.100
libswresample 0. 19.100 / 0. 19.100
libpostproc 52. 3.100 / 52. 3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'abcd.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf56.15.102
Duration: 00:00:19.48, start: 0.023220, bitrate: 572 kb/s
Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 1280x720, 573 kb/s, 5.71 fps, 30 tbr, 15360 tbn, 60 tbc (default)
Metadata:
handler_name : VideoHandler
Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 64 kb/s (default)
Metadata:
handler_name : SoundHandler
Any suggestions on why is it failing? Thanks.

It seems this question generated a lot of interest so I'm adding some more info. Following this GitHub issue Samuel from JavaCV committed some changes to allow easier access to metadata settings.
Setting metadata can be achieved through the following code snippet:
AVDictionary metadata = new AVDictionary(null);
for (Entry<String, String> e : videoMetadata.entrySet()) {
av_dict_set(metadata, e.getKey(), e.getValue(), 0);
}
video_st.metadata(metadata);
You can enable it right now by doing mvn install -Pffmpeg or wait until the next JavacV release, which should be 0.12.
PS: As you can see, this is pretty similar to what I presented in my question, so I'm not sure why it didn't work in the first place.

The FFmpegFrameRecorder class you are using uses an AVFormatContext class. Around line 2579 you can see from the method signatures, that the AVFormatContext class uses native code to implement both
public native AVDictionary metadata() method
public native AVFormatContext metadata(AVDictionary metadata) method.
The answer to the link you provided says they used the metadata property of the AVFormatContext directly - something like the first method I think. But Line 649 of FFmpegFrameRecorder uses the second method - I suspect. i.e.:
AVDictionary metadata = new AVDictionary(null);
... code to fill up dictionary ...
...
avformat_write_header(oc.metadata(metadata), options);
Unfortunately I can't try this at the moment, but I wonder if you could do something like this:
AVDictionary metadata = co.metadata();
... code to fill up dictionary ...
//I would assume at this point that oc has the metadata so
avformat_write_header(oc, (PointerPointer) null);
//if not then maybe
// avformat_write_header(oc.metadata(metadata), options);
The signature shows it is public, so I don't see why you can't get the metadata dictionary from the AVFormatContext directly. I'm not sure how the avformat_write_header method works, so I suggested two things above.
Note: I have not used this library before. I tried, unsuccessfully to use Xuggler in the past for some basic encoding.

get MPEG-TS stream media info

I'm making a player that can play an MPEG-TS stream and display all its videos at once (for monitoring purposes) in one frame using Xuggler for JAVA.
My problem is getting to determine what programs this stream holds (tv programs) and what are its streams...
for example : audio stream 1 and video stream 3 belong to program "BBC".
Now I already got it working for a .ts file by using MediaInfo http://mediaarea.net/en/MediaInfo/ like so :
MediaInfo.exe -LogFile="log.txt" "some .ts file" .... which logs a file like this :
Menu #2
ID : 1001 (0x3E9)
Menu ID : 1202 (0x4B2)
Duration : 13mn 33s
List : 2001 (0x7D1) (MPEG Video) / 3002 (0xBBA) (MPEG Audio, English)
Language : / English
Service name : NBN
Service provider : NILESAT
Service type : digital television
UTC 2006-03-28 00:00:00 : en:NBN / en:Nilesat / / / 99:00:00 / Running
and then I parsed the file in java
but I need to make this work for a live stream and when I give MediaInfo a URL instead of a file it gives this error :
Libcurl library not found
I also tried vlc commands but turns out it doesn't have this option and only available in gui (show codec information)...
the player is already working and I got an extractor too... just need this media info to work... any ideas?
EDIT : I found out FFprobe which is bundled with FFmpeg http://www.ffmpeg.org/ can do the task
but for some reason I can't read anything from the input stream.
Here's what the output looks like:
Input #0, mpegts, from 'D:\record ts\PBR_REC_20140426094852_484.ts':
Duration: N/A, start: 6164.538011, bitrate: N/A
Program 1201
Metadata:
service_name : Arabica TV
service_provider: Nilesat
Stream #0:10[0x7db]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv42
0p(tv), 720x576 [SAR 16:15 DAR 4:3], max. 2348 kb/s, 25 fps, 25 tbr, 90k tbn, 50
tbc
Stream #0:4[0xbcf]: Audio: mp2, 48000 Hz, stereo, s16p, 384 kb/s
Program 1202
I tried this in JAVA:
try {
Process process ;
Scanner sc;
ProcessBuilder processBuilder = new ProcessBuilder("C:\\Users\\vlatkozelka\\Desktop\\ffmpeg-20140623-git-ca35037-win64-static\\bin\\ffprobe.exe","-i",filename);
process=processBuilder.start();
sc=new Scanner(process.getInputStream());
process=processBuilder.start();
while(sc.hasNext()){
System.out.println(sc.nextLine());
}
} catch (IOException ex) {
Logger.getLogger(ChannelDivider.class.getName()).log(Level.SEVERE, null, ex);
}
but the sc.hasNext() just hangs like there is no input
then I tried writing to a file with cmd by using > but it gave me a blank file
however trying both methods with FFprobe -h (help command) does give output which is very much confusing me, I see output in cmd but cant read it...

I just solved this, and hope someone might make use of it:
it turns out that FFprobe was writing to stderr, not stdout,
so instead of:
getInputStream()
I used:
getErrorStream()
Now all I have to do is parse that :)

Extract files from mpeg video

Videos created with Camtasia can be shared on the web by exporting the project for the TechSmith Smart Player. The video is exported in the "H264 - MPEG-4 AVC (part10) (avc1)" codec and the export also includes other custom XML, JavaScript and SWF files used by the TechSmith Smart Player.
These custom files are also "burnt" into the video itself. For example the contents of the XML file can be viewed when opening the MP4 video in a text editor. This allows other services to only ask for the MP4 file when uploading Camtasia videos.
Therefore my question is how do you extract text and binary files from a MP4 video file? For this project I am limited to Java but I am happy to call an external executable as well.
I tried the "-dump_attachment" option in FFmpeg but that didn't work and I am out of ideas.
C:\Users\Desktop>ffmpeg -dump_attachment:t "" -i getting-started-project.mp4
ffmpeg version N-57448-gc78a416 Copyright (c) 2000-2013 the FFmpeg developers
built on Oct 26 2013 18:08:54 with gcc 4.8.2 (GCC)
configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-av
isynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enab
le-iconv --enable-libass --enable-libbluray --enable-libcaca --enable-libfreetyp
e --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --ena
ble-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-l
ibopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libsp
eex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-aa
cenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavp
ack --enable-libx264 --enable-libxavs --enable-libxvid --enable-zlib
libavutil 52. 47.101 / 52. 47.101
libavcodec 55. 38.101 / 55. 38.101
libavformat 55. 19.104 / 55. 19.104
libavdevice 55. 5.100 / 55. 5.100
libavfilter 3. 89.100 / 3. 89.100
libswscale 2. 5.101 / 2. 5.101
libswresample 0. 17.104 / 0. 17.104
libpostproc 52. 3.100 / 52. 3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'getting-started-project.mp4':
Metadata:
major_brand : mp42
minor_version : 0
compatible_brands: isommp42
creation_time : 2013-10-24 15:53:19
artist :
description :
title : Untitled
Duration: 00:05:41.12, start: 0.000000, bitrate: 314 kb/s
Stream #0:0(eng): Video: h264 (Baseline) (avc1 / 0x31637661), yuv420p(tv), 6
40x360 [SAR 1:1 DAR 16:9], 185 kb/s, 30 fps, 30 tbr, 30k tbn, 60 tbc (default)
Metadata:
creation_time : 2013-10-24 15:53:19
handler_name : Mainconcept MP4 Video Media Handler
Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 12
5 kb/s (default)
Metadata:
creation_time : 2013-10-24 15:53:19
handler_name : Mainconcept MP4 Sound Media Handler
At least one output file must be specified
Update: It appears the XML is contained within a custom UUID atom and I just need a way of extracting that.
Thanks

Managed to find a way to access the UUID Atom/Box by making use of the mp4parser project
IsoFile isoFile = new IsoFile("project.mp4");
UserBox userbox = isoFile.getBoxes(UserBox.class).get(0);
System.out.println(new String(userbox.getData()));