[FFmpeg-devel] [PATCH v2] cbs_av1: Fill tile width/height values when uniform_tile_spacing_flag is set

[Mark Thompson]

They are not explicitly in the bitstream in this case, but it is helpful
to be able to use these values without always needing to check the flag
beforehand.
---
On 31/08/2020 08:31, Wang, Fei W wrote:>> -----Original Message-----
>> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of Mark
>> Thompson
>> Sent: Sunday, August 23, 2020 6:26 AM
>> To: ffmpeg-devel at ffmpeg.org
>> Subject: [FFmpeg-devel] [PATCH] cbs_av1: Fill tile width/height values when
>> uniform_tile_spacing_flag is set
>>
>> They are not explicitly in the bitstream in this case, but it is helpful to be able to
>> use these values without always needing to check the flag beforehand.
>> ---
>>    libavcodec/cbs_av1_syntax_template.c | 9 +++++++++
>>    1 file changed, 9 insertions(+)
>>
>> diff --git a/libavcodec/cbs_av1_syntax_template.c
>> b/libavcodec/cbs_av1_syntax_template.c
>> index a315e8868a..2c976a9574 100644
>> --- a/libavcodec/cbs_av1_syntax_template.c
>> +++ b/libavcodec/cbs_av1_syntax_template.c
>> @@ -624,6 +624,15 @@ static int FUNC(tile_info)(CodedBitstreamContext *ctx,
>> RWContext *rw,
>>                current->tile_rows_log2;
>>            current->tile_rows = (sb_rows + tile_height_sb - 1) / tile_height_sb;
>>
>> +        for (i = 0; i < current->tile_cols - 1; i++)
>> +            infer(width_in_sbs_minus_1[i], tile_width_sb);
>> +        infer(width_in_sbs_minus_1[i],
>> +              sb_cols - (current->tile_cols - 1) * tile_width_sb);
> Should this by using "tile_width_sb -1" and "sb_cols - (current->tile_cols - 1) * tile_width_sb - 1" ?  And same for height_in_sbs_minus_1.

Oops, yeah (just looking at the numbers to check means you don't notice the minus_1).

>> +        for (i = 0; i < current->tile_rows - 1; i++)
>> +            infer(height_in_sbs_minus_1[i], tile_height_sb);
>> +        infer(height_in_sbs_minus_1[i],
>> +              sb_rows - (current->tile_rows - 1) * tile_height_sb);
>> +
>>        } else {
>>            int widest_tile_sb, start_sb, size_sb, max_width, max_height;
>>

New version enclosing.

Thanks,

- Mark

  libavcodec/cbs_av1_syntax_template.c | 9 +++++++++
  1 file changed, 9 insertions(+)

diff --git a/libavcodec/cbs_av1_syntax_template.c b/libavcodec/cbs_av1_syntax_template.c
index 19b82bc3f8..2d2e240e3e 100644
--- a/libavcodec/cbs_av1_syntax_template.c
+++ b/libavcodec/cbs_av1_syntax_template.c
@@ -636,6 +636,15 @@ static int FUNC(tile_info)(CodedBitstreamContext *ctx, RWContext *rw,
              current->tile_rows_log2;
          current->tile_rows = (sb_rows + tile_height_sb - 1) / tile_height_sb;

+        for (i = 0; i < current->tile_cols - 1; i++)
+            infer(width_in_sbs_minus_1[i], tile_width_sb - 1);
+        infer(width_in_sbs_minus_1[i],
+              sb_cols - (current->tile_cols - 1) * tile_width_sb - 1);
+        for (i = 0; i < current->tile_rows - 1; i++)
+            infer(height_in_sbs_minus_1[i], tile_height_sb - 1);
+        infer(height_in_sbs_minus_1[i],
+              sb_rows - (current->tile_rows - 1) * tile_height_sb - 1);
+
      } else {
          int widest_tile_sb, start_sb, size_sb, max_width, max_height;

-- 
2.28.0