[vlc-devel] [PATCH] avcodec: Fix unprotected accesses to pts

[Thomas Guillem]

so, for the Flush function, date_Set(&p_sys->pts, VLC_TICK_INVALID); could be moved after avcodec_flush_buffers( p_context ); and locks should not be needed. Right?


On Wed, Oct 2, 2019, at 13:15, Rémi Denis-Courmont wrote:
> This does not look right. If Flush really does what it's supposed to do, no other thread should be racing for the PTS.
> 
> Le 2 octobre 2019 13:05:40 GMT+03:00, "Hugo Beauzée-Luyssen" <hugo at beauzee.fr> a écrit :
>>  modules/codec/avcodec/video.c | 8 ++++++++
>>  1 file changed, 8 insertions(+)
>> 
>> diff --git a/modules/codec/avcodec/video.c b/modules/codec/avcodec/video.c
>> index d69abd7419..911fee2f8b 100644
>> --- a/modules/codec/avcodec/video.c
>> +++ b/modules/codec/avcodec/video.c
>> @@ -702,7 +702,10 @@ static void Flush( decoder_t *p_dec )
>>      decoder_sys_t *p_sys = p_dec->p_sys;
>>      AVCodecContext *p_context = p_sys->p_context;
>>  
>> +    vlc_mutex_lock(&p_sys->lock);
>>      date_Set(&p_sys->pts, VLC_TICK_INVALID); /* To make sure we recover properly */
>> +    vlc_mutex_unlock(&p_sys->lock);
>> +
>>      p_sys->i_late_frames = 0;
>>      p_sys->framedrop = FRAMEDROP_NONE;
>>      cc_Flush( &p_sys->cc );
>> @@ -759,7 +762,9 @@ static block_t * filter_earlydropped_blocks( decoder_t *p_dec, block_t *block )
>>                              "dropping frame (computer too slow ?)",
>>                       p_sys->p_context->reordered_opaque - p_sys->i_last_output_frame );
>>  
>> +            vlc_mutex_lock(&p_sys->lock);
>>              date_Set( &p_sys->pts, VLC_TICK_INVALID ); /* To make sure we recover properly */
>> +            vlc_mutex_unlock(&p_sys->lock);
>>              block_Release( block );
>>              p_sys->i_late_frames--;
>>              return NULL;
>> @@ -1339,7 +1344,10 @@ static int DecodeVideo( decoder_t *p_dec, block_t *p_block )
>>          p_sys->i_last_output_frame = -1;
>>          p_sys->framedrop = FRAMEDROP_NONE;
>>  
>> +        vlc_mutex_lock(&p_sys->lock);
>>          date_Set( &p_sys->pts, VLC_TICK_INVALID ); /* To make sure we recover properly */
>> +        vlc_mutex_unlock(&p_sys->lock);
>> +
>>          cc_Flush( &p_sys->cc );
>>  
>>          if( p_block->i_flags & BLOCK_FLAG_CORRUPTED )
> 
> -- 
> Envoyé de mon appareil Android avec Courriel K-9 Mail. Veuillez excuser ma brièveté. 
> _______________________________________________
> vlc-devel mailing list
> To unsubscribe or modify your subscription options:
> https://mailman.videolan.org/listinfo/vlc-devel
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.videolan.org/pipermail/vlc-devel/attachments/20191002/bfb70092/attachment.html>