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Perspective / D3 · Decide

Before You Buy Opus: What to Test with Your Five Free Conversions

Before buying Opus, do not spend your five free conversions proving that CineX can handle a few tiny sample clips. Use them on files that represent your real library: the kind you open most often, a subtitle-heavy video, an HDR or Dolby Vision title, your largest file, and something with multiple audio tracks. Those tests can tell you whether CineX fits your actual routine. If the files that matter most to you produce results you cannot accept, there is no reason to buy Opus.

Five tests still cannot predict every file you have not tried. CineX may only need to adjust the container for one video while another requires a full conversion, depending on the video encoding inside the file. Subtitles, HDR, file size, and audio tracks can also change what you should evaluate. The point is not to make all five tests look successful; it is to surface the limits that would matter to you before you pay.

1. Decide what you need to learn before you spend the five tests

The most useful test files are not demo clips downloaded for the occasion. They are files you actually keep, organize, and expect to watch on an iPhone, iPad, or Mac. Look through your own library first. Pick examples from the sources you use most, with the lengths, subtitle setups, and audio configurations that are normal for you.

CineX has been device-tested with MKV, MP4, AVI, and TS inputs, and it outputs MP4. But the filename extension does not tell you how the conversion will behave. Two MKV files can take different paths because the video encoding inside them differs. One may only need its container adjusted, while another may need a full conversion. So the useful question is not simply, "Can CineX convert MKV?" It is, "What happens to the MKV files I actually own?"

The five free conversions are most valuable when five real files answer one practical question: does CineX fit the files you personally need to use?

The free allowance counts successful conversions only. Failed attempts, cancellations, and retries do not consume one, while deleting a finished output does not restore a conversion. For the exact counting rules, see the free allowance guide.

2. Why tiny sample clips can give you the wrong confidence

A tiny file removes many of the conditions that make a real decision difficult. A short clip makes waiting time look trivial. A small file creates little storage pressure. A clip with no subtitles, no HDR, and one audio track tells you almost nothing about how those parts of your library will behave.

Speed is especially easy to misread. If the video is already suitable for the target MP4, CineX can adjust the container without recompressing the picture, and that path can be very quick. Other files require a full conversion and take substantially longer. A thirty-second sample may finish before that difference matters to you, even though a full-length movie would make the tradeoff obvious.

Instead of trying to make the first test "easy," give every conversion a job. One should test your normal file type. Another should test subtitles. Another should test the image characteristics you care about. When each sample represents a real use case, even an unacceptable result is useful because it tells you something that can change your decision.

3. Use the five conversions on five different risks

If HDR never appears in your library, do not waste a test on it just because it is on this list. Replace that slot with your own recurring risk: perhaps a second source of MKV files or another long video that better represents what you actually watch. The structure matters more than the exact labels: each conversion should test something you are likely to care about again.

4. Some limitations are identical in the free version and Opus

This is the distinction to keep clear before paying. The free version and Opus produce the same file quality, and there is no paid quality mode or paid speed mode. Opus is a one-time purchase that removes the conversion-count limit; it does not give the same source file a different processing result. The current price is US$8.99 in the U.S. and ¥38 in China. The Opus pricing guide covers the purchase details and what it unlocks.

If a limitation affects the files you care about most, discover it during the free tests. Opus removes the conversion-count limit; it does not remove the file-handling boundaries listed below.

If one of those points describes a core part of your library, deliberately include that kind of file in the free tests. It is more useful to learn about a blocking limitation now than to spend all five conversions on easy examples.

5. The large-file test is really about time and free storage

Do not treat the large-file test as a stunt to see how big a file CineX can handle. Its purpose is to reveal the practical cost of the kind of conversion you may repeat. When a full conversion is required, peak disk usage is roughly three times the source size. For a 10 GB video, checking that you have about 32 GB free before starting is a sensible part of the test.

Use realistic duration as well as realistic size. Some files that require a full conversion can take noticeably longer. In one tested case, 120 fps high-bit-depth material ran at about real-time speed, so ten minutes of content took roughly twelve minutes to convert. That is not a universal speed figure, but it demonstrates why a ten-second sample cannot tell you what waiting for a full-length file will feel like.

For a buying decision, I would give this test more weight than a second ordinary sample. It reveals three things at once: how long you may wait, how much free storage you need, and whether that process fits the way you actually use your device.

6. After five tests, judge the recurring use case rather than the success count

Once the tests are done, separate the results into two groups. The first is "I will encounter this repeatedly, and the output works for me." Your common files convert, subtitle behavior is acceptable, and the time and storage cost of large files fit your routine. The second is "This is a core use case, but the result is not acceptable." Perhaps image-based subtitles are essential to you, or the HDR behavior on files requiring a full conversion is a deal-breaker for your archive.

If the file types you use most produce results that fit your needs, unlimited conversions may be useful to you. If your most important recurring file type produces an unacceptable result, Opus does not fix that problem, so you do not need to buy it.

Do not give a rare edge case the same weight as something you open every week. One unusual file failing may not matter to your normal workflow. The reverse is also true: four easy successes should not outweigh one failure in the exact subtitle or image scenario you depend on. The free allowance is most useful when it helps you identify that difference.

7. Boundary: what five tests cannot tell you

Think of the five conversions as representative sampling, not a certification of your entire library. The closer those five files are to what you really use, the more useful your final buy-or-do-not-buy decision will be.

Common questions

I used all five free conversions. Can I keep testing for free?

The free version counts the first five successful conversions. Failures, cancellations, and retries do not consume a conversion, while deleting a successful output does not restore one. Opus removes the conversion-count limit.

If I buy Opus, will it fix the subtitle limitations?

No. Free and Opus produce the same file result. Text subtitles can be retained, although ASS styling is reduced to plain text. PGS, VobSub, DVD, and other image-based subtitles are not retained, and external subtitle files cannot be imported.

Are a few thirty-second clips enough for testing?

They are enough only if short, simple clips are what you normally convert. If your real library includes long videos, subtitles, HDR, or multiple audio tracks, tiny samples will not reveal the waiting time, peak storage use, or those file-handling boundaries.

If a test conversion fails, does it use one of my five?

No. Only successful conversions count toward the free allowance. Failed attempts, cancellations, and retries do not consume one.

How much free space should I have before testing a 10 GB file?

If the file requires a full conversion, peak disk usage is roughly three times the original size. For a 10 GB source, check that you have about 32 GB available before starting. Whether a full conversion is required depends on the file itself.

Axiom One LLC — CineX. Figures current as of 24 September 2026.