[FFmpeg-devel] [PATCH 01/16] avutil/buffer: add helper to allocate aligned memory

[averne]

Le 31/05/2024 à 23:44, Michael Niedermayer a écrit :
> On Fri, May 31, 2024 at 11:06:49PM +0200, averne wrote:
>> Le 30/05/2024 à 22:38, Rémi Denis-Courmont a écrit :
>>> Le torstaina 30. toukokuuta 2024, 22.43.03 EEST averne a écrit :
>>>> This is useful eg. for memory-mapped buffers that need page-aligned memory,
>>>> when dealing with hardware devices
>>>>
>>>> Signed-off-by: averne <averne381 at gmail.com>
>>>> ---
>>>>  libavutil/buffer.c | 31 +++++++++++++++++++++++++++++++
>>>>  libavutil/buffer.h |  7 +++++++
>>>>  2 files changed, 38 insertions(+)
>>>>
>>>> diff --git a/libavutil/buffer.c b/libavutil/buffer.c
>>>> index e4562a79b1..b8e357f540 100644
>>>> --- a/libavutil/buffer.c
>>>> +++ b/libavutil/buffer.c
>>>> @@ -16,9 +16,14 @@
>>>>   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
>>>> USA */
>>>>
>>>> +#include "config.h"
>>>> +
>>>>  #include <stdatomic.h>
>>>>  #include <stdint.h>
>>>>  #include <string.h>
>>>> +#if HAVE_MALLOC_H
>>>> +#include <malloc.h>
>>>> +#endif
>>>>
>>>>  #include "avassert.h"
>>>>  #include "buffer_internal.h"
>>>> @@ -100,6 +105,32 @@ AVBufferRef *av_buffer_allocz(size_t size)
>>>>      return ret;
>>>>  }
>>>>
>>>> +AVBufferRef *av_buffer_aligned_alloc(size_t size, size_t align)
>>>> +{
>>>> +    AVBufferRef *ret = NULL;
>>>> +    uint8_t    *data = NULL;
>>>> +
>>>> +#if HAVE_POSIX_MEMALIGN
>>>> +    if (posix_memalign((void **)&data, align, size))
>>>
>>> Invalid cast.
>>>
>>
>> Neither gcc or clang emit a warning here, even on -Weverything.
>> What would be your idea of a valid cast then? First cast to intptr_t, 
>> then void** ?
>>
>>>> +        return NULL;
>>>> +#elif HAVE_ALIGNED_MALLOC
>>>> +    data = aligned_alloc(align, size);
> 
> on mingw64:
> 
> src/libavutil/buffer.c: In function ‘av_buffer_aligned_alloc’:
> src/libavutil/buffer.c:117:12: error: implicit declaration of function ‘aligned_alloc’ [-Werror=implicit-function-declaration]
>   117 |     data = aligned_alloc(align, size);
>       |            ^~~~~~~~~~~~~
> 
> thx

Missing include of stdlib.h, probably. Will fix, thanks.