[FFmpeg-devel] [PATCH 1/2] fftools/opt_common: Use %c instead of %s to write single char

[Andreas Rheinhardt]

James Almer:
> On 7/30/2023 9:47 PM, Andreas Rheinhardt wrote:
>> Also combine multiple printfs.
>>
>> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
>> ---
>>   fftools/opt_common.c | 28 ++++++++++++++--------------
>>   1 file changed, 14 insertions(+), 14 deletions(-)
>>
>> diff --git a/fftools/opt_common.c b/fftools/opt_common.c
>> index 7c996f140d..3881d5bbef 100644
>> --- a/fftools/opt_common.c
>> +++ b/fftools/opt_common.c
>> @@ -692,14 +692,13 @@ int show_codecs(void *optctx, const char *opt,
>> const char *arg)
>>           if (strstr(desc->name, "_deprecated"))
>>               continue;
>>   -        printf(" ");
>> -        printf(avcodec_find_decoder(desc->id) ? "D" : ".");
>> -        printf(avcodec_find_encoder(desc->id) ? "E" : ".");
>> -
>> -        printf("%c", get_media_type_char(desc->type));
>> -        printf((desc->props & AV_CODEC_PROP_INTRA_ONLY) ? "I" : ".");
>> -        printf((desc->props & AV_CODEC_PROP_LOSSY)      ? "L" : ".");
>> -        printf((desc->props & AV_CODEC_PROP_LOSSLESS)   ? "S" : ".");
>> +        printf(" %c%c%c%c%c%c",
>> +               avcodec_find_decoder(desc->id) ? 'D' : '.',
>> +               avcodec_find_encoder(desc->id) ? 'E' : '.',
>> +               get_media_type_char(desc->type),
>> +               (desc->props & AV_CODEC_PROP_INTRA_ONLY) ? 'I' : '.',
>> +               (desc->props & AV_CODEC_PROP_LOSSY)      ? 'L' : '.',
>> +               (desc->props & AV_CODEC_PROP_LOSSLESS)   ? 'S' : '.');
>>             printf(" %-20s %s", desc->name, desc->long_name ?
>> desc->long_name : "");
>>   @@ -747,12 +746,13 @@ static void print_codecs(int encoder)
>>           void *iter = NULL;
>>             while ((codec = next_codec_for_id(desc->id, &iter,
>> encoder))) {
>> -            printf(" %c", get_media_type_char(desc->type));
>> -            printf((codec->capabilities & AV_CODEC_CAP_FRAME_THREADS)
>> ? "F" : ".");
>> -            printf((codec->capabilities & AV_CODEC_CAP_SLICE_THREADS)
>> ? "S" : ".");
>> -            printf((codec->capabilities & AV_CODEC_CAP_EXPERIMENTAL) 
>> ? "X" : ".");
>> -            printf((codec->capabilities &
>> AV_CODEC_CAP_DRAW_HORIZ_BAND)?"B" : ".");
>> -            printf((codec->capabilities & AV_CODEC_CAP_DR1)          
>> ? "D" : ".");
>> +            printf(" %c%c%c%c%c%c",
>> +                   get_media_type_char(desc->type),
>> +                   (codec->capabilities &
>> AV_CODEC_CAP_FRAME_THREADS)   ? 'F' : '.',
>> +                   (codec->capabilities &
>> AV_CODEC_CAP_SLICE_THREADS)   ? 'S' : '.',
>> +                   (codec->capabilities &
>> AV_CODEC_CAP_EXPERIMENTAL)    ? 'X' : '.',
>> +                   (codec->capabilities &
>> AV_CODEC_CAP_DRAW_HORIZ_BAND) ? 'B' : '.',
>> +                   (codec->capabilities &
>> AV_CODEC_CAP_DR1)             ? 'D' : '.');
>>                 printf(" %-20s %s", codec->name, codec->long_name ?
>> codec->long_name : "");
>>               if (strcmp(codec->name, desc->name))
> 
> You could instead port this function to AVBPrint, to only print to
> stderr once.

I do not think this is a good idea as it would add another potential
source of errors (for the implicit (re)allocations that happen when
using the AVBPrint API).

- Andreas