[FIX] Handle row_count decrease

[moveman]

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---

We found ccextractor cannot handle row_count decreasing well. When row count decreases, the upper row should be displaced while the bottom row should be kept. Before the fix, the srt is like this:

104
00:04:05,795 --> 00:04:06,295
{\an4}A roll-up caption's depth

105
00:04:07,296 --> 00:04:07,330
{\an4}A roll-up caption's depth

106
00:04:08,264 --> 00:04:08,297
{\an4}A roll-up caption's depth

107%  |  04:11
00:04:08,298 --> 00:04:12,034
{\an2}A roll-up caption's depth
displayed, like this.

108%  |  04:14
00:04:12,068 --> 00:04:14,770
{\an5}(CC1) Demonstration of
paint-on style captions:

After the fix, the srt is like this:

104
00:04:05,795 --> 00:04:06,295
{\an4}A roll-up caption's depth

105
00:04:07,296 --> 00:04:07,330
{\an4}A roll-up caption's depth
can be decreased after

106
00:04:08,264 --> 00:04:08,297
{\an2}can be decreased after
the caption has been

107%  |  04:11
00:04:08,298 --> 00:04:12,034
{\an2}the caption has been
displayed, like this.

108%  |  04:14
00:04:12,068 --> 00:04:14,770
{\an5}(CC1) Demonstration of
paint-on style captions:

The cea708 log of the original ccExtractor is included here: 708.log

The cea708 log of the fixed ccExtractor is included here: new_708.log

Expected captions:

[cfsmp3]

LGTM, but be aware that since we are migrating to Rust it's possible this change gets lost if not ported.

[steel-bucket]

Hi, can you please rebase so we could check the regression tests. Thanks

[ccextractor-bot]

CCExtractor CI platform finished running the test files on linux. Below is a summary of the test results, when compared to test for commit 39e051b...:

Report Name	Tests Passed
Broken	13/13
CEA-708	13/14
DVB	7/7
DVD	3/3
DVR-MS	2/2
General	27/27
Hauppage	3/3
MP4	3/3
NoCC	10/10
Options	85/86
Teletext	21/21
WTV	13/13
XDS	34/34

NOTE: The following tests have been failing on the master branch as well as the PR:

• ccextractor --service 1 --out=txt f17524b53f..., Last passed:

  Never

• ccextractor --unicode c83f765c66..., Last passed:

  Never

All tests passing on the master branch were passed completely.

Check the result page for more info.

[ccextractor-bot]

CCExtractor CI platform finished running the test files on windows. Below is a summary of the test results, when compared to test for commit a34ba0f...:

Report Name	Tests Passed
Broken	13/13
CEA-708	13/14
DVB	4/7
DVD	3/3
DVR-MS	2/2
General	27/27
Hauppage	3/3
MP4	3/3
NoCC	10/10
Options	86/86
Teletext	21/21
WTV	10/13
XDS	34/34

Your PR breaks these cases:

• ccextractor --service 1 --out=txt f17524b53f...

NOTE: The following tests have been failing on the master branch as well as the PR:

• ccextractor --stdout --quiet --no-fontcolor 79a51f3500..., Last passed:

  Never

• ccextractor --stdout --quiet --no-fontcolor 767b546f96..., Last passed:

  Never

• ccextractor --autoprogram --out=srt --latin1 --quant 0 85271be4d2..., Last passed:

  Never

• ccextractor --out=srt --latin1 f23a544ba8..., Last passed:

  Never

• ccextractor --out=srt --latin1 10f0f77cf4..., Last passed:

  Test 5993

• ccextractor --out=srt --latin1 df3b4d62d3..., Last passed:

  Never

It seems that not all tests were passed completely. This is an indication that the output of some files is not as expected (but might be according to you).

Check the result page for more info.