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Household DVD + R / RW recorder BBK 9915S
The first consumer devices for recording video to optical media were exotic products, as they used less common DVD-RAM discs. DVD + RW is the more widespread and compatible format, so recorders writing to such discs have a fairly good chance of becoming more popular devices.
At the moment there are many DVD + RW models, from almost every well-known manufacturer. The main drawback of most models that hinders widespread distribution is that the cost is too high so far, reaching $ 1000. However, more affordable recorders are emerging. For example, the 9915S model from BBK, a very popular company in Russia, can be found on sale for $ 350.
Using this unit as an example, we will also try to understand what household DVD + RW recorders are capable of, what tasks they are capable of.
Player, general view
Passport technical characteristics
Video outputs
Composite +
S-Video +
SCART +
-composite +
-S-Video no
-RGBS +
Component +
NTSC-PAL + transcoder (full, bi-directional, on in menu)
Progressive scan +
Video DAC 27 MHz / 11 bit
Video inputs
Composite 2 pcs.
S-Video 2 pcs.
digital video input DV (i.LINK / IEEE1394) +
SECAM TV tuner, antenna coaxial (75 Ohm) input and output
Audio outputs
Analog Stereo Out +
Multichannel analog + (5.1)
Coaxial digital +
Optical digital +
Built-in DD / DTS decoder + / no
Audio DAC 96 kHz / 24 bit
Audio inputs
Analog stereo input 2 pcs.
Dimensions W x H x D (mm) 430 x 79 x 295
Weight (kg) 3.9
Price (at the time of writing) $ 350
Link to the manufacturer's website 🔗
Outside
If there are files supported by the format recorder on the disc in the root directory, then, as soon as it recognizes such a disc, it starts playing them. At the same time, jpg and mp3 (wma) files are displayed simultaneously and independently of each other. The user can control this process using the navigation panel (called by the NAVIGATION button).
MP3 navigation
The type of navigation - by pictures or by files with music - is switched by the first icon button at the top of this panel. At the bottom left is a list of files and directories, and on the right side of the navigation pane is the current programmed playlist. In fact, there are only two ways to play files: either from the current directory, or according to a programmed list.That is, in order to play all the files from the disc, you will either have to sequentially move from directory to directory, or program the playback of all files. Another disadvantage: the first 20 characters are displayed in the names of files and directories, but if there is no description of the file system in the Joliet format on the disk, then they are reduced to 8 (or even 6 with a tilde and number) characters; squares are displayed instead of Russian letters; no support for tags; the pause between mp3 tracks is more than 0.5 seconds; there is no fast rewinding through mp3 tracks, and there is rewinding through CD-DA tracks, but the sound “stutters” at the same time; There is only one icon for music files and for files with pictures - a note. For pleasant trifles, we add the ability to choose one of 16 transition effects from one picture to another, or set a random selection of the type of transition.
Recording
Video recording is possible only on DVD + R / RW discs with 6 video sources: two composite (front and rear), S-Video (front and rear), DV input (front only, small four-pin) and from the built-in TV- tuner. The process is very simple: load a suitable (non-finalized!) Blank into the player, select the desired video source (using the SOURCE button),
If necessary, the recording is paused with the PAUSE button. There are 4 recording modes: HQ (high quality, 60 min recording), SP (good quality, 120 min), EP (reduced quality, 240 min), SPL (low quality, 360 min). Recording times are based on a blank 4.7 GB disc. Recording will automatically pause when the video signal is lost. There is also a configurable timer to automatically shut off the recording after 15, 30, 60 or 90 minutes. Greater flexibility is provided by the "Scheduled Recording Manager".
Record, Scheduler
With its help, you can specify the source (in the case of a TV tuner and the channel), quality, frequency (specific date, day of the week or daily) and start and end times of the recording. Of course, you must first set the recorder's timer to the correct time. The biggest inconvenience is that the timer and other settings are reset during the shortest power outages.
If the DV-input is selected as the signal source, then it becomes possible to control the DV-camera connected to this input - the PLAY, REV and FWD buttons work accordingly, and when you press the RECORD button, the camera starts playback synchronously.
The result of recording on a DVD + R disc cannot be changed: a disc menu is automatically generated, containing as many thumbnails as there were recording sessions, a caption for each is generated automatically, and the picture is the first frame from the recorded fragment. The only thing that can be done is to add one more fragment (if there is still space) or to finalize the disc, that is, to make it readable on ordinary DVD drives. Recording of the following tracks after finalization is not possible.
With DVD + RW discs, the situation is more interesting.
Record, DV-RW
On such a disc, all records or only the last one can be deleted, the disc can be locked (and subsequently unlocked) from recording or editing, in addition, it is possible to manually divide the received records into chapters, hide a separate chapter from playback, change the preview picture in the disc menu to any frame from the corresponding record and change the caption under the picture. In order for the resulting DVD + RW disc to be readable on conventional drives, it must be made compatible. Important warning: operations related to recording and editing of discs take some time, during which it is not recommended to turn off the power of the recorder. A power failure in the case of working with DVD + RW can lead to the loss of all recordings, and make a DVD + R disc unusable.
Video path testing, playback
Brightness Clarity (TVL)
Composite over 540 Excellent
S-Video over 540 Excellent
SCART-RGB 540 (no contrast) Very good
Component over 540 Excellent
576p 530 Good
480p 500 Medium
Color fidelity (TVL)
Composite 130 Excellent
S-Video 130 Excellent
SCART-RGB over 170 Good
Component 250 Very good
576p 230 Very good
480p 220 Very good
The results of objective tests of the video path are generally positive. I was not pleased only by a sharp decrease in brightness definition for a progressive 480p signal to 500 TVL. Color gradients and gray scale in the entire range were reproduced without artifacts, and the brightness of the fragments in the captured image practically did not differ from the brightness on the original test pattern. Thus, the fact that the player does not provide for any image settings is not a big drawback - the picture is already correct, if only the display device would show it adequately. The player has a built-in deinterlacing function, i.e. converting the original interlaced image into a progressive one. Progressive mode is activated either in the menu, or by pressing the IS / PS button on the remote control. In progressive mode, video is only output to the component video output. The deinterlacing algorithm is primitive: only fragments that do not change over several frames are displayed in frame-by-frame mode, dynamic ones are displayed in fields. As you would expect, this IP conversion method results in numerous artifacts in the form of jagged vertical edges of moving objects (the so-called "hairbrush"). As a result, considering the reduction in luminance and color definition in progressive mode, the value of this function is low.
A bi-directional transcoder (PAL-NTSC, activated by the PAL / NTSC button on the remote control and in the menu), on the contrary, works very well, but, unfortunately, there is no mode in which the output video signal format would correspond to the source. In other words, to avoid some degradation of the image, it is necessary to determine the system in which the video disc is recorded and manually turn off the transcoder. By the way, the OSD of the recorder is optimized for PAL format: as you can see in some screenshots, it looks much worse in NTSC due to interpolation from 576 lines to 480.
Video path testing, recording
Before moving on to discussing the results of the tests for the recording quality, let's pay a little attention to the image source inside the recorder - the TV tuner. We see the three most likely video sources for this recorder: DV camera, analog camera or video player and internal TV tuner. With the first, everything is clear - the DV-input is almost directly connected to the encoder chip and the quality of the capture from the DV camera will most likely be determined by the quality of encoding in MPEG-2. Digitizing the signal from the low-frequency inputs is also not difficult (we hope that the Philips chip will not let you down), but with the TV tuner, everything is not so simple. Moreover, as it turned out, using an external one will not work: for some reason (although the SAA7115HL decoder is multi-format) feeding a SECAM video signal to external inputs results in a black-and-white picture with noises.
Well, the sensitivity and selectivity of the built-in TV tuner turned out to be not bad: on an indoor antenna in unfavorable conditions, the recorder picked up a TV signal almost as well as a JVC TV. The picture looks good overall, the colors are bright and correct, but the clarity was not high. In contrast, the image of a woman's face captured from the BBK-9915S TV tuner looks as if a Gaussian Blur filter with a 2 pixel radius has been applied to it, while the image captured from the composite output of a JVC TV looks quite in focus.
TV, bbk TV, JVC
Fragments of television frames. Left: source - composite output of BBK-9915S, receiving on its tuner, right: source - composite output of JVC TV. In both cases, the reception was carried out on a collective antenna. Pictures refer to full frames.
The tests, during which a DV camera was connected to the recorder, led to the expected results: firstly, the SONY camera really performs the most primitive actions according to the commands from the recorder, and secondly, the image quality did not suffer much when compressed into an MPEG-2 stream. There are a little more compression artifacts, a little less detail, in general, the loss of quality is insignificant.
bbk-dv-hq sony-dv
Left: a fragment of a frame taken from a video recording with maximum quality (HQ), obtained by capturing an image with a BBK-9915S recorder from a SONY DV camera via the DV interface. Right: the same fragment, but the frame was captured via the DV interface to a computer, that is, without any transformation. Pictures refer to full frames; for clarity, the fragments are enlarged 2 times.
Notes: 1. The frame is difficult to compress, since the picture is dynamic - the car was filmed "in the wiring", which means that the differences between the consecutive frames are large.
2. The above frames are composed of two fields, so everything is in the "combs".
Finally, we recorded a piece from Toy Story 2 with different quality levels. The fragment contained both dynamic and static scenes, in some scenes there were many contrasting objects with small details, in others there were few. The source of the video signal was a Creative Dxr-2 MPEG-2 decoder card connected to the recorder via an S-Video interface. The obtained parameters of the recorded fragments are shown in the table:
Clip number Quality Video stream bitrate, Mbps Audio stream bitrate, kbps Resolution
min. Max. average
1 HQ 7.9 9.8 8.7 384 720 × 576
2 SP 1.6 7.25 4.3 256 720 × 576
3 EP 0.8 5.3 2.2 256 352 × 576
4 SPL 1.36 1.5 1.5 128 352 × 288
We "grabbed" the resulting DVD onto the hard drive and analyzed the video fragments (clips 1-4) using the CyberLink PowerDVD 4.0 software player. We also captured the same fragment (clip 5, recording to an avi file with minimal compression) from the S-Video output of the Creative Dxr-2 board with an ASUS V9250VS video card and, for control, used the original DVD with this fragment from Toy Story 2 (clip 6).
First of all, we compared clip 5 and clip 6. When viewed on a computer monitor, the differences between the clips are minimal, but a closer analysis revealed that, firstly, in clip 5, the color resolution is about 2 times lower (S-Video limitation interface) than in clip 6, and, secondly, the contrast is slightly lower (the problem of the video capture unit of the ASUS V9250VS card when capturing video via the S-Video input). Thus, we came to the conclusion that clip 5 can be used to check the quality of digitizing and compressing video material by the BBK-9915S recorder, since its quality is certainly better than any of clips 1-4, i.e. clip 5 gives an idea of how what is being input to the S-Video input of the recorder.
Next, we compared clip 5 with clips 1-4. According to our subjective impressions, the difference between HQ recording (clip 1) and clip 5 is not very big: on dynamic scenes on large gradients in HQ, compression artifacts appear in the form of "squares" and, in general, that's all. Recording in SP mode (clip 2) is characterized by the fact that it is difficult to ignore such artifacts, but you can watch such video on a small TV. Watching the recording in EP quality (Clip 3) gives the impression that the video source is a VHS player: a lot of artifacts and general blurring of the image. We can describe the video image in SPL mode (clip 4) in one phrase: very low quality. The sound, by the way, does not cause disgust in SPL: on a VHS cassette, not in Hi-Fi mode, it is much worse.
Let's summarize the intermediate result:
Recording mode Optimal use:
HQ for capturing video from DV input or S-Video input
SP for recording from built-in TV tuner or composite input
EP for digitizing VHS cassette
SPL when the main thing is a long recording duration, not quality
During operations with a DVD + R disc recorded on BBK-9915S, it turned out that after finalization, the disc can most likely be played on consumer DVD-players. At least the bbk-969S player has played all the recorded fragments without any artifacts. At the same time, the BBK-9915S recorder itself, for some reason, played the recording in the minimum quality (SPL) mode with a magnification of about 1.5 times, that is, the central part of the clip was stretched to full screen, and the edges of the image were cropped. In addition, pressing the button to go to the previous chapter was completely ignored by him. Software DVD players played back the burned disc with varying success: using the same DVD drive, CyberLink PowerDVD 4.0 coped with this task on one computer, and crashed on another without even having time to load the disc menu. Analysis of the disk structure showed that the VIDEO_TS directory contains three versions of the complete set of * .ifo, * .bup and * .vob files, while the total size of files according to the data from their attributes was three times larger than the amount of information recorded on the disk.When I tried to simply copy these files to the hard drive, an error message was displayed, but DVD Decrypter in ifo mode was able to copy the entire contents of the disc in chapters. Thus, DVD-discs recorded on the BBK-9915S are somewhat different from regular DVD-video discs, which means that problems when playing them on various devices are quite possible.
Testing the audio path
RightMark Audio Analyzer 5.4
Test circuit: CD-DA 16 bit 44 kHz Stereo Analog Out => Lynx Two Measurement Interface Line In
Operating mode: 16 bit 44 kHz
Frequency response (from 40 Hz to 15 kHz), dB: +0.04, -0.06 Excellent
Noise level, dB (A): -94.7 Very good
Dynamic range, dB (A): 94.5 Very good
Nelin. distortion,%: 0.0019 Excellent
Intermod. distortion,%: 0.021 Good
Interpenetration of channels, dB: -92.3 Excellent
Overall rating: Very good (Detailed report).
Circuit under test: CD-DA 16-bit 44 kHz, stereo, digital coaxial output => digital input of the Lynx Two measurement interface
Operating mode: 16 bit 44 kHz
Uneven frequency response (from 40 Hz to 15 kHz), dB: +0.00, -0.00 Excellent
Noise level, dB (A): -97.8 Excellent
Dynamic range, dB (A): 97.8 Excellent
Nelin. distortion,%: 0.0003 Excellent
Intermod. distortion,%: 0.0058 Excellent
Interpenetration of channels, dB: -98.1 Excellent
Overall rating: Excellent (Detailed report).
Since the characteristics of the audio signal recorded from the digital output of the BBK-9915S do not differ from the reference, this means that no oversampling occurs during CD-DA playback and the signal is transmitted bit-for-bit. An interesting feature of this DVD recorder is that changing the volume (VOL +/- buttons on the remote control) changes both the analog signal level and the digital signal amplitude. By the way, the level of the analog signal at maximum volume corresponds to the standard for household audio equipment, so normalization was not required in the RMAA program. Analysis of the analog signal revealed a fairly high level of intermodulation distortion, as well as an incomprehensible hump on the graph for the right channel in the test for interpenetration of stereo channels. Since the same hump was found in the analysis of a digital audio signal, we considered it an artifact, and the interpenetration of the channels was assessed by the left channel.
conclusions
DVD-recorder BBK-9915S is a functionally rich device that provides both basic functions for playing DVD-video discs and the ability to record on DVD + R / RW from analog (composite and S-Video) inputs, from digital (DV-input) and from the built-in tuner that supports the SECAM system.
Advantages:
Good localization (Russified on-screen menu and competent guide in Russian);
Good selectivity and sensitivity of the built-in TV tuner;
There is a DV-input;
As many as 4 types of video outputs (composite, S-Video, SCART-RGB and component);
Possibility of limited editing of recordings on DVD + RW.
Disadvantages:
Poor video quality in progressive mode;
Primitive deinterlacing algorithm;
Low definition of the built-in TV tuner;
Lack of multi-channel 5.1 settings;
No DTS decoder;
A momentary power failure resets the timer and all settings;
Compatibility issues may arise when playing DVDs recorded with this recorder;
There is no play mode for all mp3 (wma) files contained on the disc.
From our point of view, this device can be used for digitizing a video archive on VHS tapes and for distilling video from DV cameras (especially if for some reason a computer is not suitable for this). In addition, the built-in TV tuner and recording scheduler allow for scheduled recording of TV programs, but two hours of video in SP mode may not be enough for recording full-length movies with commercials.
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