[FFmpeg-devel] [PATCH 1/3] avcodec/avs3_parser: set has_b_frames properly

[FFmpeg-devel] [PATCH 1/3] avcodec/avs3_parser: set has_b_frames properly

[Zhao Zhili]

has_b_frames should be output_reorder_delay field in AVS3 sequence
header and larger than 1. The parser implementation doesn't parse
that field. Decoder can set has_b_frames properly, so use FFMAX
here to avoid resetting has_b_frames from output_reorder_delay to 1.
---
 libavcodec/avs3_parser.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/avs3_parser.c b/libavcodec/avs3_parser.c
index d04d96a03a..0d2e940d1e 100644
--- a/libavcodec/avs3_parser.c
+++ b/libavcodec/avs3_parser.c
@@ -114,7 +114,7 @@ static void parse_avs3_nal_units(AVCodecParserContext *s, const uint8_t *buf,
             //            bitrate_high(12)
             skip_bits(&gb, 32);
 
-            avctx->has_b_frames = !get_bits(&gb, 1);
+            avctx->has_b_frames = FFMAX(avctx->has_b_frames, !get_bits(&gb, 1));
 
             avctx->framerate.num = avctx->time_base.den = ff_avs3_frame_rate_tab[ratecode].num;
             avctx->framerate.den = avctx->time_base.num = ff_avs3_frame_rate_tab[ratecode].den;
-- 
2.35.3

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

Re: [FFmpeg-devel] [PATCH 1/3] avcodec/avs3_parser: set has_b_frames properly

[Andreas Rheinhardt]

Zhao Zhili:
> has_b_frames should be output_reorder_delay field in AVS3 sequence
> header and larger than 1. The parser implementation doesn't parse
> that field. Decoder can set has_b_frames properly, so use FFMAX
> here to avoid resetting has_b_frames from output_reorder_delay to 1.
> ---
>  libavcodec/avs3_parser.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/libavcodec/avs3_parser.c b/libavcodec/avs3_parser.c
> index d04d96a03a..0d2e940d1e 100644
> --- a/libavcodec/avs3_parser.c
> +++ b/libavcodec/avs3_parser.c
> @@ -114,7 +114,7 @@ static void parse_avs3_nal_units(AVCodecParserContext *s, const uint8_t *buf,
>              //            bitrate_high(12)
>              skip_bits(&gb, 32);
>  
> -            avctx->has_b_frames = !get_bits(&gb, 1);
> +            avctx->has_b_frames = FFMAX(avctx->has_b_frames, !get_bits(&gb, 1));
>  
>              avctx->framerate.num = avctx->time_base.den = ff_avs3_frame_rate_tab[ratecode].num;
>              avctx->framerate.den = avctx->time_base.num = ff_avs3_frame_rate_tab[ratecode].den;

FFMAX can evaluate its arguments more than once which is not intended here.

- Andreas
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

[FFmpeg-devel] [PATCH v2 1/3] avcodec/avs3_parser: set has_b_frames properly

[Zhao Zhili]

has_b_frames should be output_reorder_delay field in AVS3 sequence
header and larger than 1. The parser implementation doesn't parse
that field. Decoder can set has_b_frames properly, so use FFMAX
here to avoid resetting has_b_frames from output_reorder_delay to 1.
---
 libavcodec/avs3_parser.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/libavcodec/avs3_parser.c b/libavcodec/avs3_parser.c
index d04d96a03a..a9fd879e9d 100644
--- a/libavcodec/avs3_parser.c
+++ b/libavcodec/avs3_parser.c
@@ -71,7 +71,7 @@ static void parse_avs3_nal_units(AVCodecParserContext *s, const uint8_t *buf,
     if (buf[0] == 0x0 && buf[1] == 0x0 && buf[2] == 0x1) {
         if (buf[3] == AVS3_SEQ_START_CODE) {
             GetBitContext gb;
-            int profile, ratecode;
+            int profile, ratecode, low_delay;
 
             init_get_bits8(&gb, buf + 4, buf_size - 4);
 
@@ -114,7 +114,8 @@ static void parse_avs3_nal_units(AVCodecParserContext *s, const uint8_t *buf,
             //            bitrate_high(12)
             skip_bits(&gb, 32);
 
-            avctx->has_b_frames = !get_bits(&gb, 1);
+            low_delay = get_bits(&gb, 1);
+            avctx->has_b_frames = FFMAX(avctx->has_b_frames, !low_delay);
 
             avctx->framerate.num = avctx->time_base.den = ff_avs3_frame_rate_tab[ratecode].num;
             avctx->framerate.den = avctx->time_base.num = ff_avs3_frame_rate_tab[ratecode].den;
-- 
2.35.3

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

Re: [FFmpeg-devel] [PATCH 1/3] avcodec/avs3_parser: set has_b_frames properly

["zhilizhao(赵志立)"]

> On May 13, 2022, at 5:43 PM, Andreas Rheinhardt <andreas.rheinhardt@outlook.com> wrote:
> 
> Zhao Zhili:
>> has_b_frames should be output_reorder_delay field in AVS3 sequence
>> header and larger than 1. The parser implementation doesn't parse
>> that field. Decoder can set has_b_frames properly, so use FFMAX
>> here to avoid resetting has_b_frames from output_reorder_delay to 1.
>> ---
>> libavcodec/avs3_parser.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/libavcodec/avs3_parser.c b/libavcodec/avs3_parser.c
>> index d04d96a03a..0d2e940d1e 100644
>> --- a/libavcodec/avs3_parser.c
>> +++ b/libavcodec/avs3_parser.c
>> @@ -114,7 +114,7 @@ static void parse_avs3_nal_units(AVCodecParserContext *s, const uint8_t *buf,
>>             //            bitrate_high(12)
>>             skip_bits(&gb, 32);
>> 
>> -            avctx->has_b_frames = !get_bits(&gb, 1);
>> +            avctx->has_b_frames = FFMAX(avctx->has_b_frames, !get_bits(&gb, 1));
>> 
>>             avctx->framerate.num = avctx->time_base.den = ff_avs3_frame_rate_tab[ratecode].num;
>>             avctx->framerate.den = avctx->time_base.num = ff_avs3_frame_rate_tab[ratecode].den;
> 
> FFMAX can evaluate its arguments more than once which is not intended here.

Good catch, thanks! Here is v2:
http://ffmpeg.org/pipermail/ffmpeg-devel/2022-May/296396.html

Use a variable low_delay to fix the FFMAX issue and serve as document.

> 
> - Andreas
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

Re: [FFmpeg-devel] [PATCH v2 1/3] avcodec/avs3_parser: set has_b_frames properly

["zhilizhao(赵志立)"]

> On May 13, 2022, at 6:12 PM, Zhao Zhili <quinkblack@foxmail.com> wrote:
> 
> has_b_frames should be output_reorder_delay field in AVS3 sequence
> header and larger than 1. The parser implementation doesn't parse
> that field. Decoder can set has_b_frames properly, so use FFMAX
> here to avoid resetting has_b_frames from output_reorder_delay to 1.
> ---
> libavcodec/avs3_parser.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/libavcodec/avs3_parser.c b/libavcodec/avs3_parser.c
> index d04d96a03a..a9fd879e9d 100644
> --- a/libavcodec/avs3_parser.c
> +++ b/libavcodec/avs3_parser.c
> @@ -71,7 +71,7 @@ static void parse_avs3_nal_units(AVCodecParserContext *s, const uint8_t *buf,
>     if (buf[0] == 0x0 && buf[1] == 0x0 && buf[2] == 0x1) {
>         if (buf[3] == AVS3_SEQ_START_CODE) {
>             GetBitContext gb;
> -            int profile, ratecode;
> +            int profile, ratecode, low_delay;
> 
>             init_get_bits8(&gb, buf + 4, buf_size - 4);
> 
> @@ -114,7 +114,8 @@ static void parse_avs3_nal_units(AVCodecParserContext *s, const uint8_t *buf,
>             //            bitrate_high(12)
>             skip_bits(&gb, 32);
> 
> -            avctx->has_b_frames = !get_bits(&gb, 1);
> +            low_delay = get_bits(&gb, 1);
> +            avctx->has_b_frames = FFMAX(avctx->has_b_frames, !low_delay);
> 
>             avctx->framerate.num = avctx->time_base.den = ff_avs3_frame_rate_tab[ratecode].num;
>             avctx->framerate.den = avctx->time_base.num = ff_avs3_frame_rate_tab[ratecode].den;
> -- 
> 2.35.3
> 

Will apply this patchset tomorrow unless there are objections.
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".