[FFmpeg-devel] [PATCH v4 7/7] lavc/bsf: make BSF iteration the same as other iterators

[Muhammad Faiz]

On Sat, Feb 3, 2018 at 5:39 PM, wm4 <nfxjfg at googlemail.com> wrote:
> On Fri,  2 Feb 2018 19:44:18 +0000
> Josh de Kock <josh at itanimul.li> wrote:
>
>> ---
>>  fftools/cmdutils.c             |  2 +-
>>  libavcodec/avcodec.h           |  6 +++++-
>>  libavcodec/bitstream_filter.c  |  4 ++--
>>  libavcodec/bitstream_filters.c | 29 ++++++++++++++++++-----------
>>  4 files changed, 26 insertions(+), 15 deletions(-)
>>
>> diff --git a/fftools/cmdutils.c b/fftools/cmdutils.c
>> index 9ecc51b..0b06ccc 100644
>> --- a/fftools/cmdutils.c
>> +++ b/fftools/cmdutils.c
>> @@ -1586,7 +1586,7 @@ int show_bsfs(void *optctx, const char *opt, const char *arg)
>>      void *opaque = NULL;
>>
>>      printf("Bitstream filters:\n");
>> -    while ((bsf = av_bsf_next(&opaque)))
>> +    while ((bsf = av_bsf_iterate(&opaque)))
>>          printf("%s\n", bsf->name);
>>      printf("\n");
>>      return 0;
>> diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
>> index 99f5fb9..c41779a 100644
>> --- a/libavcodec/avcodec.h
>> +++ b/libavcodec/avcodec.h
>> @@ -5728,7 +5728,7 @@ attribute_deprecated
>>  void av_bitstream_filter_close(AVBitStreamFilterContext *bsf);
>>  /**
>>   * @deprecated the old bitstream filtering API (using AVBitStreamFilterContext)
>> - * is deprecated. Use av_bsf_next() from the new bitstream filtering API (using
>> + * is deprecated. Use av_bsf_iterate() from the new bitstream filtering API (using
>>   * AVBSFContext).
>>   */
>>  attribute_deprecated
>> @@ -5750,7 +5750,11 @@ const AVBitStreamFilter *av_bsf_get_by_name(const char *name);
>>   * @return the next registered bitstream filter or NULL when the iteration is
>>   *         finished
>>   */
>> +const AVBitStreamFilter *av_bsf_iterate(void **opaque);
>> +#if FF_API_NEXT
>> +attribute_deprecated
>>  const AVBitStreamFilter *av_bsf_next(void **opaque);
>> +#endif
>>
>>  /**
>>   * Allocate a context for a given bitstream filter. The caller must fill in the
>> diff --git a/libavcodec/bitstream_filter.c b/libavcodec/bitstream_filter.c
>> index ed1cf33..ca11ed3 100644
>> --- a/libavcodec/bitstream_filter.c
>> +++ b/libavcodec/bitstream_filter.c
>> @@ -34,9 +34,9 @@ const AVBitStreamFilter *av_bitstream_filter_next(const AVBitStreamFilter *f)
>>      void *opaque = NULL;
>>
>>      while (filter != f)
>> -        filter = av_bsf_next(&opaque);
>> +        filter = av_bsf_iterate(&opaque);
>>
>> -    return av_bsf_next(&opaque);
>> +    return av_bsf_iterate(&opaque);
>>  }
>>
>>  void av_register_bitstream_filter(AVBitStreamFilter *bsf)
>> diff --git a/libavcodec/bitstream_filters.c b/libavcodec/bitstream_filters.c
>> index 7b0cb50..338ef82 100644
>> --- a/libavcodec/bitstream_filters.c
>> +++ b/libavcodec/bitstream_filters.c
>> @@ -52,7 +52,7 @@ extern const AVBitStreamFilter ff_vp9_superframe_split_bsf;
>>
>>  #include "libavcodec/bsf_list.c"
>>
>> -const AVBitStreamFilter *av_bsf_next(void **opaque)
>> +const AVBitStreamFilter *av_bsf_iterate(void **opaque)
>>  {
>>      uintptr_t i = (uintptr_t)*opaque;
>>      const AVBitStreamFilter *f = bitstream_filters[i];
>> @@ -63,12 +63,18 @@ const AVBitStreamFilter *av_bsf_next(void **opaque)
>>      return f;
>>  }
>>
>> +#if FF_API_NEXT
>> +const AVBitStreamFilter *av_bsf_next(void **opaque) {
>> +    return av_bsf_iterate(opaque);
>> +}
>> +#endif
>> +
>>  const AVBitStreamFilter *av_bsf_get_by_name(const char *name)
>>  {
>> -    int i;
>> +    const AVBitStreamFilter *f = NULL;
>> +    void *i = 0;
>>
>> -    for (i = 0; bitstream_filters[i]; i++) {
>> -        const AVBitStreamFilter *f = bitstream_filters[i];
>> +    while ((f = av_bsf_iterate(&i))) {
>>          if (!strcmp(f->name, name))
>>              return f;
>>      }
>> @@ -78,19 +84,20 @@ const AVBitStreamFilter *av_bsf_get_by_name(const char *name)
>>
>>  const AVClass *ff_bsf_child_class_next(const AVClass *prev)
>>  {
>> -    int i;
>> +    const AVBitStreamFilter *f = NULL;
>> +    void *i = 0;
>>
>>      /* find the filter that corresponds to prev */
>> -    for (i = 0; prev && bitstream_filters[i]; i++) {
>> -        if (bitstream_filters[i]->priv_class == prev) {
>> -            i++;
>> +    while (prev && (f = av_bsf_iterate(&i))) {
>> +        if (f->priv_class == prev) {
>>              break;
>>          }
>>      }
>>
>>      /* find next filter with priv options */
>> -    for (; bitstream_filters[i]; i++)
>> -        if (bitstream_filters[i]->priv_class)
>> -            return bitstream_filters[i]->priv_class;
>> +    while ((f = av_bsf_iterate(&i))) {
>> +        if (f->priv_class)
>> +            return f->priv_class;
>> +    }
>>      return NULL;
>>  }
>
> I like _next better than _iterate (as others have also said), but I
> think I can tolerate it. At least it'll be consistent across all those
> APIs.

What about av*iterate(int index)?
As you suggested in
https://ffmpeg.org/pipermail/ffmpeg-devel/2018-January/224702.html

Anyway av_bsf_iterate() previously didn't exist, so we can freely
choose how it will be called (with int index or void **opaque).

Thank's.