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• Interfacing to an Xbox Optical Drive

  1er octobre 2013, par Multimedia Mike — xbox

  The next generation Xbox is going to hit the streets soon. But for some reason, I’m still interested in the previous generation’s unit (i.e., the original Xbox). Specifically, I’ve always wondered if it’s possible to use the original Xbox’s optical drive in order to read Xbox discs from Linux. I was never curious enough to actually buy an Xbox just to find out but I eventually came across a cast-off console on a recycle pile.

  I have long known that the Xbox has what appears to be a more or less standard optical drive with a 40-pin IDE connector. The only difference is the power adapter which I surmise is probably the easiest way to turn a bit of standardized hardware into a bit of proprietary hardware. The IDE and power connectors look like this :

  
  
  

  Thus, I wanted to try opening an Xbox and plugging the optical drive into a regular PC, albeit one that supports IDE cables, and allow the Xbox to supply power to the drive. Do you still have hardware laying around that has 40-pin IDE connectors ? I guess my Mac Mini PPC fits the bill, but I’ll be darned if I’m going to pry that thing open again. I have another IDE-capable machine buried in my closet, last called into service when I needed a computer with a native RS-232 port 3 years ago. The ordeal surrounding making this old computer useful right now can be another post entirely.

  Here’s what the monstrosity looks like thanks to characteristically short IDE cable lengths :

  
  

  

  Click for larger image

  
  

  Process :

  1. Turn on Xbox first
  2. Turn on PC

  Doing these things in the opposite order won’t work since the kernel really wants to see the drive when booting up. Inspecting the 'dmesg' log afterward reveals interesting items :
  

  <br />
hdd: PHILIPS XBOX DVD DRIVE, ATAPI CD/DVD-ROM drive<br />
hdd: host max PIO5 wanted PIO255(auto-tune) selected PIO4<br />
hdd: UDMA/33 mode selected<br />
[...]<br />
hdd: ATAPI DVD-ROM drive, 128kB Cache<br />

  Why is that interesting ? When is the last time to saw disk devices prefixed by ‘hd’ rather than ‘sd’ ? Blast from the past. Oh, and the optical drive’s vendor string clearly indicates that this is an Xbox drive saying ‘hi !’.

  Time To Read
  When I first studied an Xbox disc in a normal optical drive, I noticed that I was able to read 6992 2048-byte sectors — about 14 MB of data — as reported by the disc table of contents (TOC). This is just enough data to play a standard DVD video animation that kindly instructs the viewer to please use a proper Xbox. At this point, I estimated that there must be something special about Xbox optical drive firmware that knows how to read alternate information on these discs and access further sectors.

  I ran my TOC query tool with an Xbox Magazine demo disc in the optical drive and it reported substantially more than 6992 sectors, enough to account for more than 2 GB of data. That’s promising. I then tried running 'dd' against the device and it was able to read… about 14 MB, an exact quantity of bytes that, when divided by 2048 bytes/sector, yields 6992 sectors.

  Future (Past ?) Work
  Assuming Google is your primary window into the broader internet, the world is beginning to lose its memory of things pertaining to the original Xbox (Microsoft’s naming scheme certainly doesn’t help searches). What I’m saying is that it can be difficult to find information about this stuff now. However, I was able to learn that a host needs to perform a sort of cryptographic handshake with the drive at the SCSI level before it is allowed to access the forbidden areas of the disc. I think. I’m still investigating this and will hopefully post more soon.

• FFMPEG : TS video copied to MP4, missing 3 first frames [closed]

  21 août 2023, par Vasilis Lemonidis

  Running :

  


  ffmpeg -i test.ts -fflags +genpts -c copy -y test.mp4


  


  for this test.ts, which has 30 frames, readable by opencv, I end up with 28 frames, out of which 27 are readable by opencv. More specifically :

  


  ffprobe -v error -select_streams v:0 -count_packets  -show_entries stream=nb_read_packets -of csv=p=0 tmp.ts 


  


  returns 30.

  


  ffprobe -v error -select_streams v:0 -count_packets     -show_entries stream=nb_read_packets -of csv=p=0 tmp.mp4


  


  returns 28.

  


  Using OpenCV in that manner

  


  cap = cv2.VideoCapture(tmp_path)
readMat = []
while cap.isOpened():
        ret, frame = cap.read()
        if not ret:
            break
        readMat.append(frame)


  


  I get for the ts file 30 frames, while for the mp4 27 frames.

  


  Could someone explain why the discrepancies ? I get no error during the transformation from ts to mp4 :

  


  ffmpeg version N-111746-gd53acf452f Copyright (c) 2000-2023 the FFmpeg developers
  built with gcc 11.3.0 (GCC)
  configuration: --ld=g++ --bindir=/bin --extra-libs='-lpthread -lm' --pkg-config-flags=--static --enable-static --enable-gpl --enable-libaom --enable-libass --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libsvtav1 --enable-libdav1d --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-nonfree --enable-cuda-nvcc --enable-cuvid --enable-nvenc --enable-libnpp 
  libavutil      58. 16.101 / 58. 16.101
  libavcodec     60. 23.100 / 60. 23.100
  libavformat    60. 10.100 / 60. 10.100
  libavdevice    60.  2.101 / 60.  2.101
  libavfilter     9. 10.100 /  9. 10.100
  libswscale      7.  3.100 /  7.  3.100
  libswresample   4. 11.100 /  4. 11.100
  libpostproc    57.  2.100 / 57.  2.100
[mpegts @ 0x4237240] DTS discontinuity in stream 0: packet 5 with DTS 306003, packet 6 with DTS 396001
Input #0, mpegts, from 'tmp.ts':
  Duration: 00:00:21.33, start: 3.400000, bitrate: 15 kb/s
  Program 1 
    Metadata:
      service_name    : Service01
      service_provider: FFmpeg
  Stream #0:0[0x100]: Video: h264 (High) ([27][0][0][0] / 0x001B), yuv420p(progressive), 300x300, 1 fps, 3 tbr, 90k tbn
Output #0, mp4, to 'test.mp4':
  Metadata:
    encoder         : Lavf60.10.100
  Stream #0:0: Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 300x300, q=2-31, 1 fps, 3 tbr, 90k tbn
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
[out#0/mp4 @ 0x423e280] video:25kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 4.192123%
frame=   30 fps=0.0 q=-1.0 Lsize=      26kB time=00:00:21.00 bitrate=  10.3kbits/s speed=1e+04x 


  


  Additional information

  


  The origin of the video I am processing comes from a continuous stitching operation of still images ts videos, produced by this class update method :

  


  import cv2
import os
import subprocess
from tempfile import NamedTemporaryFile
class VideoUpdater:
    def __init__(
        self, video_path: str, framerate: int, timePerFrame: Optional[int] = None
    ):
        """
        Video updater takes in a video path, and updates it using a supplied frame, based on a given framerate.
        Args:
            video_path: str: Specify the path to the video file
            framerate: int: Set the frame rate of the video
        """
        if not video_path.endswith(".mp4"):
            LOGGER.warning(
                f"File type {os.path.splitext(video_path)[1]} not supported for streaming, switching to ts"
            )
            video_path = os.path.splitext(video_path)[0] + ".mp4"

        self._ps = None
        self.env = {
            
        }
        self.ffmpeg = "/usr/bin/ffmpeg "

        self.video_path = video_path
        self.ts_path = video_path.replace(".mp4", ".ts")
        self.tfile = None
        self.framerate = framerate
        self._video = None
        self.last_frame = None
        self.curr_frame = None


    def update(self, frame: np.ndarray):
        if len(frame.shape) == 2:
            frame = cv2.cvtColor(frame, cv2.COLOR_GRAY2BGR)
        else:
            frame = cv2.cvtColor(frame, cv2.COLOR_RGB2BGR)
        self.writeFrame(frame)

    def writeFrame(self, frame: np.ndarray):
        """
        The writeFrame function takes a frame and writes it to the video file.
        Args:
            frame: np.ndarray: Write the frame to a temporary file
        """


        tImLFrame = NamedTemporaryFile(suffix=".png")
        tVidLFrame = NamedTemporaryFile(suffix=".ts")

        cv2.imwrite(tImLFrame.name, frame)
        ps = subprocess.Popen(
            self.ffmpeg
            + rf"-loop 1 -r {self.framerate} -i {tImLFrame.name} -t {self.framerate} -vcodec libx264 -pix_fmt yuv420p -y {tVidLFrame.name}",
            env=self.env,
            shell=True,
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE,
        )
        ps.communicate()
        if os.path.isfile(self.ts_path):
            # this does not work to watch, as timestamps are not updated
            ps = subprocess.Popen(
                self.ffmpeg
                + rf'-i "concat:{self.ts_path}|{tVidLFrame.name}" -c copy -y {self.ts_path.replace(".ts", ".bak.ts")}',
                env=self.env,
                shell=True,
                stdout=subprocess.PIPE,
                stderr=subprocess.PIPE,
            )
            ps.communicate()
            shutil.move(self.ts_path.replace(".ts", ".bak.ts"), self.ts_path)

        else:
            shutil.copyfile(tVidLFrame.name, self.ts_path)
        # fixing timestamps, we dont have to wait for this operation
        ps = subprocess.Popen(
            self.ffmpeg
            + rf"-i {self.ts_path} -fflags +genpts -c copy -y {self.video_path}",
            env=self.env,
            shell=True,
            # stdout=subprocess.PIPE,
            # stderr=subprocess.PIPE,
        )
        tImLFrame.close()
        tVidLFrame.close()


  


• Weird commandline behaviour when running a batch script. Script will only work if another script is being run first [closed]

  31 décembre 2022, par Macster

  TLDR ;
  
In cmd.exe
  &#xA;makedir.bat only <= Not working
  &#xA;new.bat then makedir.bat <= Working

  &#xA;

  I'm new to batch and noticed a weird behaviour when running a scrip.

  &#xA;

  It basically takes the last entry(Video file path) from a textfile and uses the path inside a ffmpeg command to get the file duration. But it's not working. makedir.bat

  &#xA;

  What I know is that the part which gets the path is working on it's own, and so does the part that gets the duration.

  &#xA;

  Now, if I run a second script, new.bat, which is actually just the part that gets the files duration and outputs the right duration(22 Seconds), before running makedir.bat, suddenly makedir.bat starts working as intended, even though set /a duration=2*3600*60+*1 in the output is wrong. But thats only for cmd.exe. It wont work for PowerShell.&#xA;Whats going on ? Is the script faulty or is there some kind of caching in the cmd.exe ?

  &#xA;

  EDIT : Oh, and if I run makedir.bat first and then new.bat, new.bat wont work anymore.

  &#xA;

  makedir.bat

  &#xA;

  ::Get last entry from "mylist.txt"
for /f "delims=" %%a in ('type mylist.txt ^| findstr /b /c:"file"') do set path=%%a

::Trim path for file name
set video_path=%path:~32,-1%

echo %video_path%

::Get the video duration
for /f "tokens=1* delims=:" %%a in ('ffmpeg -i %video_path% 2^>^&1 ^| findstr "Duration"') do set duration=%%b

set duration=%duration:~0,12%
set /a duration=%duration:~1,2%*3600+%duration:~4,2%*60+%duration:~7,2%*1
echo %duration%


  &#xA;

  new.bat

  &#xA;

  for /F "tokens=1* delims=:" %%a in ('ffmpeg -i pipshort1.webm 2^>^&1 ^| findstr "Duration"') do set duration=%%b
set duration=%duration:~0,12%
set /a duration=%duration:~1,2%*3600+%duration:~4,2%*60+%duration:~7,2%*1


  &#xA;

  Ouput makedir.bat

  &#xA;

  >for /F "delims=" %a in ('type mylist.txt | findstr /b /c:"file"') do set path=%a

>set path=file '/webapp/stream/videos/pip/transparent_short.webm'

>set path=file '/webapp/stream/videos/pip/transparent_short.webm'

>set path=file '/webapp/stream/videos/pip/transparent_short.webm'

>set path=file '/webapp/stream/videos/pip/pipshort1.webm'

>set video_path=pipshort1.webm

>echo pipshort1.webm
pipshort1.webm

>for /F "tokens=1* delims=:" %a in ('ffmpeg -i pipshort1.webm 2>&1 | findstr "Duration"') do set duration=%b

>set duration=~0,12

>set /a duration=0,*3600+2*60+*1
Missing operator

>echo 0
0


  &#xA;

  Output new.bat + makedir.bat

  &#xA;

  >new.bat

>for /F "tokens=1* delims=:" %a in ('ffmpeg -i pipshort1.webm 2>&1 | findstr "Duration"') do set duration=%b

>set duration= 00:00:22.02, start: 0.000000, bitrate: 2337 kb/s

>set duration= 00:00:22.02

>set /a duration=00*3600+00*60+22*1

>echo 22
22

>makedir.bat

>for /F "delims=" %a in ('type mylist.txt | findstr /b /c:"file"') do set path=%a

>set path=file '/webapp/stream/videos/pip/transparent_short.webm'

>set path=file '/webapp/stream/videos/pip/transparent_short.webm'

>set path=file '/webapp/stream/videos/pip/transparent_short.webm'

>set path=file '/webapp/stream/videos/pip/pipshort1.webm'

>set video_path=pipshort1.webm

>echo pipshort1.webm
pipshort1.webm

>for /F "tokens=1* delims=:" %a in ('ffmpeg -i pipshort1.webm 2>&1 | findstr "Duration"') do set duration=%b

>set duration=22

>set /a duration=2*3600+*60+*1
Missing operator

>echo 22
22


  &#xA;