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• ffmpeg encoding .mp4 fails in safari when hosted from s3. handbrake encoded video works first time

  11 juin 2018, par Simon Rogers

  The mp4 videos I’ve encoded with ffmpeg work perfectly in Safari if stored locally, but break if hosted from s3. I have tried countless encoding settings to no avail.

  However having just run a mov quickly through Handbrake and ticking ’optimise for web’ and encoding baseline @ 4.0, this has worked perfectly first time.

  I don’t understand what could be going wrong with my ffmpeg encoding.

  Things I have noticed about files from two separate encoders which work :

  They both have yuv420p(tv, bt709) whereas ffmpeg is just saying yuv420p – this is the only thing I can identify from ffprobe that is consistently different.

  I have done a fresh install of ffmpeg to no avail :

  ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

  brew install ffmpeg --with-fdk-aac --with-ffplay --with-freetype --with-libass  --with-libvorbis --with-libvpx --with-opus --with-x265

  This error appears in all the files I have encoded with ffmpeg :

  Unsupported codec with id 0 for input stream 1

  ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

  mp4box gives the following for the ffmpeg video, which doesn’t work :

   Tempuras-iMac:tests tempura$ mp4box -info /Users/tempura/tests/mov-output-10-1400.mp4
  
  * Movie Info *
  
  Timescale 1000 - 1 track
  
  Computed Duration 00:00:10.967 - Indicated Duration 00:00:10.967
  
  Fragmented File: no
  
  File suitable for progressive download (moov before mdat)
  
  File Brand isom - version 512
  
      Compatible brands: isom iso2 avc1 mp41
  
  Created: UNKNOWN DATE   Modified: UNKNOWN DATE
  
  File has no MPEG4 IOD/OD
  
  
  
  iTunes Info:
  
  Encoder Software: Lavf58.12.100
  
  1 UDTA types: meta (1) 
  
  
  
  Track # 1 Info - TrackID 1 - TimeScale 15360
  
  Media Duration 00:00:10.966 - Indicated Duration 00:00:10.966
  
  Track has 1 edit lists: track duration is 00:00:10.967
  
  Media Info: Language "English (eng)" - Type "vide:avc1" - 329 samples
  
  Visual Track layout: x=0 y=0 width=1800 height=1200
  
  MPEG-4 Config: Visual Stream - ObjectTypeIndication 0x21
  
  AVC/H264 Video - Visual Size 1800 x 1200
  
  AVC Info: 1 SPS - 1 PPS - Profile Baseline @ Level 4
  
  NAL Unit length bits: 32
  
  Pixel Aspect Ratio 1:1 - Indicated track size 1800 x 1200
  
  Chroma format YUV 4:2:0 - Luma bit depth 8 - chroma bit depth 8
  
  SPS#1 hash: 2BD106A8DFD73B92825D87D4D312B22F9CEC1986
  
  PPS#1 hash: 656AE5F3BE854F3C8B889E72310662390F18EDBD
  
  Self-synchronized
  
  RFC6381 Codec Parameters: avc1.42C028
  
  Average GOP length: 329 samples

  And gives the following for two videos that do work.

  First :

  Tempuras-iMac:tests tempura$ mp4box -info /Users/tempura/tests/mov-output-05-1400.mp4 
  
  [iso file] Unknown box type tmcd
  
  [iso file] Read Box type  (0x00000000) has size 0 but is not at root/file level, skipping
  
   * Movie Info *
  
  Timescale 1000 - 2 tracks
  
  Computed Duration 00:00:10.967 - Indicated Duration 00:00:10.967
  
  Fragmented File: no
  
  File suitable for progressive download (moov before mdat)
  
  File Brand isom - version 512
  
      Compatible brands: isom iso2 avc1 mp41
  
  Created: UNKNOWN DATE   Modified: UNKNOWN DATE
  
  File has no MPEG4 IOD/OD
  
  
  
  iTunes Info:
  
  Encoder Software: Lavf58.12.100
  
  1 UDTA types: meta (1) 
  
  
  
  Track # 1 Info - TrackID 1 - TimeScale 15360
  
  Media Duration 00:00:10.966 - Indicated Duration 00:00:10.966
  
  Track has 1 edit lists: track duration is 00:00:10.967
  
  Media Info: Language "English (eng)" - Type "vide:avc1" - 329 samples
  
  Visual Track layout: x=0 y=0 width=1800 height=1200
  
  MPEG-4 Config: Visual Stream - ObjectTypeIndication 0x21
  
  AVC/H264 Video - Visual Size 1800 x 1200
  
  AVC Info: 1 SPS - 1 PPS - Profile Baseline @ Level 4
  
  NAL Unit length bits: 32
  
  Pixel Aspect Ratio 1:1 - Indicated track size 1800 x 1200
  
  Chroma format YUV 4:2:0 - Luma bit depth 8 - chroma bit depth 8
  
  SPS#1 hash: 39D86732FD5F78B18F2E83C651FAE38EA0E30A6D
  
  PPS#1 hash: 656AE5F3BE854F3C8B889E72310662390F18EDBD
  
  Self-synchronized
  
  RFC6381 Codec Parameters: avc1.42C028
  
  Average GOP length: 329 samples
  
  
  
  Track # 2 Info - TrackID 2 - TimeScale 15360
  
  Media Duration 00:00:10.966 - Indicated Duration 00:00:10.966
  
  Track has 1 edit lists: track duration is 00:00:10.967
  
  Track is disabled
  
  Media Info: Language "Undetermined (und)" - Type "tmcd:tmcd" - 1 samples
  
  Unknown media type
  
  RFC6381 Codec Parameters: tmcd
  
  All samples are sync

  Second :

  Tempuras-iMac:tests tempura$ mp4box -info /Users/tempura/Documents/yes_2106.mp4 
  
  * Movie Info *
  
  Timescale 30000 - 1 track
  
  Computed Duration 00:00:10.966 - Indicated Duration 00:00:10.966
  
  Fragmented File: no
  
  File suitable for progressive download (moov before mdat)
  
  File Brand isom - version 1
  
      Compatible brands: isom avc1 mp42
  
  Created: GMT Fri Jun  1 11:24:54 2018
  
  Modified: GMT Fri Jun  1 11:24:54 2018
  
  
  
  File has root IOD (9 bytes)
  
  Scene PL 0xff - Graphics PL 0xff - OD PL 0xff
  
  Visual PL: ISO Reserved Profile (0x15)
  
  Audio PL: No audio capability required (0xff)
  
  No streams included in root OD
  
  
  
  Track # 1 Info - TrackID 1 - TimeScale 30
  
  Media Duration 00:00:10.966 - Indicated Duration 00:00:10.966
  
  Media Info: Language "Undetermined (und)" - Type "vide:avc1" - 329 samples
  
  Visual Track layout: x=0 y=0 width=1800 height=1200
  
  MPEG-4 Config: Visual Stream - ObjectTypeIndication 0x21
  
  AVC/H264 Video - Visual Size 1800 x 1200
  
  AVC Info: 1 SPS - 1 PPS - Profile Baseline @ Level 4.2
  
  NAL Unit length bits: 32
  
  Pixel Aspect Ratio 1:1 - Indicated track size 1800 x 1200
  
  Chroma format YUV 4:2:0 - Luma bit depth 8 - chroma bit depth 8
  
  SPS#1 hash: ED5CFE0A3F65F36ADCFA347C1273A29784E8AEAC
  
  PPS#1 hash: 7ECF7597FDDAC5F8C82B54BFB40A1F9A8D8807FA
  
  Self-synchronized
  
  RFC6381 Codec Parameters: avc1.42C02A
  
  Average GOP length: 329 samples

• Can't view and record graph at the same time using FFMpegWriter [closed]

  7 juillet 2024, par Barkın Özer

  So this code is used for graphing and logging sensor data coming from bluetooth ports. I wanted to add an function that will record the graph in mp4 format. In order to achieve this I used ffmpegWriter. The issue is while this code records the graph I can't view the graph at the same time.

  


  import serial
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation, FFMpegWriter
import openpyxl
from datetime import datetime

# Constants
GRAVITY = 9.81  # Standard gravity in m/s²

# Initialize serial connections to HC-06 devices
ser_x_accel = serial.Serial('COM4', 9600, timeout=1)  # X-axis acceleration data
ser_y_angle = serial.Serial('COM11', 9600, timeout=1)  # Y-axis angle data

# Initialize empty lists to store data
x_accel_data = []
y_angle_data = []
timestamps = []

# Initialize Excel workbook
wb = openpyxl.Workbook()
ws = wb.active
ws.title = "Sensor Data"
ws.append(["Timestamp", "X Acceleration (m/s²)", "Y Angle (degrees)"])

# Function to update the plot and log data
def update(frame):
    # Read data from serial connections
    line_x_accel = ser_x_accel.readline().decode('utf-8').strip()
    line_y_angle = ser_y_angle.readline().decode('utf-8').strip()
    
    try:
        # Parse and process X-axis acceleration data
        x_accel_g = float(line_x_accel)  # Acceleration in g read from serial
        x_accel_ms2 = x_accel_g * GRAVITY  # Convert from g to m/s²
        x_accel_data.append(x_accel_ms2)
        
        # Parse and process Y-axis angle data
        y_angle = float(line_y_angle)
        y_angle_data.append(y_angle)
        
        # Append timestamp
        timestamps.append(datetime.now())

        # Limit data points to show only the latest 100
        if len(x_accel_data) > 100:
            x_accel_data.pop(0)
            y_angle_data.pop(0)
            timestamps.pop(0)

        # Log data to Excel with timestamp
        timestamp_str = timestamps[-1].strftime("%H:%M:%S")
        ws.append([timestamp_str, x_accel_data[-1], y_angle_data[-1]])

        # Clear and update plots
        ax1.clear()
        ax1.plot(timestamps, x_accel_data, label='X Acceleration', color='b')
        ax1.legend(loc='upper left')
        ax1.set_ylim([-20, 20])  # Adjust based on expected acceleration range in m/s²
        ax1.set_title('Real-time X Acceleration Data')
        ax1.set_xlabel('Time')
        ax1.set_ylabel('Acceleration (m/s²)')
        ax1.grid(True)

        ax2.clear()
        ax2.plot(timestamps, y_angle_data, label='Y Angle', color='g')
        ax2.legend(loc='upper left')
        ax2.set_ylim([-180, 180])
        ax2.set_title('Real-time Y Angle Data')
        ax2.set_xlabel('Time')
        ax2.set_ylabel('Angle (degrees)')
        ax2.grid(True)

        # Update text boxes with latest values
        text_box.set_text(f'X Acceleration: {x_accel_data[-1]:.2f} m/s²')
        text_box2.set_text(f'Y Angle: {y_angle_data[-1]:.2f}°')
        
        # Save the workbook periodically (every 100 updates)
        if frame % 100 == 0:
            wb.save("sensor_data.xlsx")
        
    except ValueError:
        pass  # Ignore lines that are not properly formatted

# Setup the plots
fig, (ax1, ax2) = plt.subplots(2, 1, figsize=(10, 8))
text_box = ax1.text(0.05, 0.95, '', transform=ax1.transAxes, fontsize=12, verticalalignment='top', bbox=dict(boxstyle='round', facecolor='wheat', alpha=0.5))
text_box2 = ax2.text(0.05, 0.95, '', transform=ax2.transAxes, fontsize=12, verticalalignment='top', bbox=dict(boxstyle='round', facecolor='wheat', alpha=0.5))

# Animate the plots
ani = FuncAnimation(fig, update, interval=100)  # Update interval of 100ms

# Save the animation as a video file
writer = FFMpegWriter(fps=10, metadata=dict(artist='Me'), bitrate=1800)
ani.save("sensor_data.mp4", writer=writer)

plt.tight_layout()
plt.show()

# Save the workbook at the end of the session
wb.save("sensor_data.xlsx")



  


  I tried using OpenCV to record the graph but then I didn't even got any recording. I think solving this issue with my original code would be a better approach.

  


• Dreamcast Anniversary Programming

  10 septembre 2010, par Multimedia Mike — Game Hacking

  This day last year saw a lot of nostalgia posts on the internet regarding the Sega Dreamcast, launched 10 years prior to that day (on 9/9/99). Regrettably, none of the retrospectives that I read really seemed to mention the homebrew potential, which is the aspect that interested me. On the occasion of the DC’s 11th anniversary, I wanted to remind myself how to build something for the unit and do so using modern equipment and build tools.

  
  
  

  Background
  Like many other programmers, I initially gained interest in programming because I desired to program video games. Not content to just plunk out games on a PC, I always had a deep, abiding ambition to program actual video game hardware. That is, I wanted to program a purpose-built video game console. The Sega Dreamcast might be the most ideal candidate to ever emerge for that task. All that was required to run your own software on the unit was the console, a PC, some free software tools, and a special connectivity measure.

  The Equipment
  Here is the hardware required (ideally) to build software for the DC :

  • The console itself (I happen to have 3 of them laying around, as pictured above)
  • Some peripherals : Such as the basic DC controller, the DC keyboard (flagship title : Typing of the Dead), and the visual memory unit (VMU)
    
    
    
  • VGA box : The DC supported 480p gaming via a device that allowed you to connect the console straight to a VGA monitor via 15-pin D-sub. Not required for development, but very useful. I happen to have 3 of them from different third parties :
    
    
    
  • Finally, the connectivity measure for hooking the DC to the PC.
    There are 2 options here. The first is rare, expensive and relatively fast : A DC broadband adapter. The second is slower but much less expensive and relatively easy to come by– the DC coder’s cable. This was a DB-9 adapter on one end and a DC serial adapter on the other, and a circuit in the middle to monkey with voltage levels or some such ; I’m no electrical engineer. I procured this model from the notorious Lik Sang, well before that outfit was sued out of business.
    
    
    

  Dealing With Legacy
  Take a look at that coder’s cable again. DB-9 ? When was the last time you owned a computer with one of those ? And then think farther back to the last time to had occasion to plug something into one of those ports (likely a serial mouse).

  
  
  

  A few years ago, someone was about to toss out this Belkin USB to DB-9 serial converter when I intervened. I foresaw the day when I would dust off the coder’s cable. So now I can connect a USB serial cable to my Eee PC, which then connects via converter to a different serial cable, one which has its own conversion circuit that alters the connection to yet another type of serial cable.

  Bits is bits is bits as far as I’m concerned.

  
  
  

  Putting It All Together
  Now to assemble all the pieces (plus a monitor) into one development desktop :

  
  
  

  The monitor says “dcload 1.0.3, idle…”. That’s a custom boot CD-ROM that is patiently waiting to receive commands, code and data via the serial port.

  Getting The Software
  Back in the day, homebrew software development on the DC revolved around these components :

  • GNU binutils : for building base toolchains for the Hitachi SH-4 main CPU as well as the ARM7-based audio coprocessor
  • GNU gcc/g++ : for building compilers on top of binutils for the 2 CPUs
  • Newlib : a C library intended for embedded systems
  • KallistiOS : an open source, real-time OS developed for the DC

  The DC was my first exposure to building cross compilers. I developed some software for the DC in the earlier part of the decade. Now, I am trying to figure out how I did it, especially since I think I came up with a few interesting ideas at the time.

  Struggling With the Software Legacy
  The source for KallistiOS has gone untouched since about 2004 but is still around thanks to Sourceforge. The instructions for properly building the toolchain have been lost to time, or would be were it not for the Internet Archive’s copy of a site called Hangar Eleven. Also, KallistiOS makes reference to a program called ‘dc-tool’ which is needed on the client side for communicating with dcload. I was able to find this binary at the Boob ! site (well-known in DC circles).

  I was able to build the toolchain using binutils 2.20.1, gcc 4.5.1 and newlib 1.18.0. Building the toolchain is an odd process as it requires building the binutils, then building the C compiler, then newlib, and then building the C compiler again along with the C++ compiler because the C++ compiler depends on newlib.

  With some effort, I got the toolchain to build KallistiOS and most of its example programs. I documented most of the tweaks I had to make, several of them exactly the same as this one that I recently discovered while resurrecting a 10-year-old C program (common construct in C programming of old ?).

  Moment of Truth
  So I had some example programs built as ELF files. I told dc-tool to upload and run them on the waiting console. Unfortunately, the tool would just sort of stall, though some communication had evidently taken place. It has been many years since I have seen this in action but I recall that something more ought to be happening.

  Plan B (Hardware)
  This is the point that I remember that I have been holding onto one rather old little machine that still has a DB-9 serial port. It’s not especially ergonomic to set up. I have to run it on my floor because, to connect it to my network, I need to run a 25′ ethernet cable that just barely reaches from the other room. The machine doesn’t seem to like USB keyboards, which is a shame since I have long since ditched any PS/2 keyboards. Fortunately, the box still has an old Gentoo distro and is running sshd, a holdover from its former life as a headless box.

  
  
  

  Now when I run dc-tool, both the PC and DC report the upload progress while pretty overscan bars oscillate on the DC’s monitor. Now I’m back in business, until…

  Plan C (Software)
  None of these KallistiOS example programs are working. Some are even reporting catastrophic failures (register dumps) via the serial console. That’s when I remember that gcc can be a bit fickle on CPU architectures that are not, shall we say, first-class citizens. Back in the day, gcc 2.95 was a certified no-go for SH-4 development. 3.0.3 or 3.0.4 was called upon at the time. As I’m hosting this toolchain on x86_64 right now, gcc 3.0.4 can’t even be built (predates the architecture).

  One last option : As I searched through my old DC project directories, I found that I still have a lot of the resulting binaries, the ones I built 7-8 years ago. I upload a few of those and I finally see homebrew programming at work again, including this old program (described in detail here).

  Next Steps
  If I ever feel like revisiting this again, I suppose I can try some of the older 4.x series to see if they build valid programs. Alternatively, try building an x86_32-hosted 3.0.4 toolchain which ought to be a known good. And if that fails, search a little bit more to find that there are still active Dreamcast communities out there on the internet which probably have development toolchain binaries ready for download.