avcodec: scale pts values to libavcodec scale

Otherwise bitrate control is quite fobar.

Fixes #11538

Pointed out by Sesse

modules/codec/avcodec/encoder.c

@@ -1017,7 +1017,7 @@ static void vlc_av_packet_Release(block_t *block)
     free(b);
 }
 
-static block_t *vlc_av_packet_Wrap(AVPacket *packet, mtime_t i_length)
+static block_t *vlc_av_packet_Wrap(AVPacket *packet, mtime_t i_length, AVCodecContext *context )
 {
     vlc_av_packet_t *b = malloc( sizeof( *b ) );
     if( unlikely(b == NULL) )
@@ -1035,6 +1035,8 @@ static block_t *vlc_av_packet_Wrap(AVPacket *packet, mtime_t i_length)
     p_block->i_dts = packet->dts;
     if( unlikely( packet->flags & AV_PKT_FLAG_CORRUPT ) )
         p_block->i_flags |= BLOCK_FLAG_CORRUPTED;
+    p_block->i_pts = p_block->i_pts * CLOCK_FREQ * context->time_base.num / context->time_base.den;
+    p_block->i_dts = p_block->i_dts * CLOCK_FREQ * context->time_base.num / context->time_base.den;
 
     return p_block;
 }
@@ -1064,8 +1066,14 @@ static block_t *EncodeVideo( encoder_t *p_enc, picture_t *p_pict )
         frame->interlaced_frame = !p_pict->b_progressive;
         frame->top_field_first = !!p_pict->b_top_field_first;
 
-        /* Set the pts of the frame being encoded */
-        frame->pts = (p_pict->date == VLC_TS_INVALID) ? AV_NOPTS_VALUE : p_pict->date;
+        /* Set the pts of the frame being encoded
+         * avcodec likes pts to be in time_base units
+         * frame number */
+        if( likely( p_pict->date > VLC_TS_INVALID ) )
+            frame->pts = p_pict->date * p_sys->p_context->time_base.den /
+                          CLOCK_FREQ / p_sys->p_context->time_base.num;
+        else
+            frame->pts = AV_NOPTS_VALUE;
 
         if ( p_sys->b_hurry_up && frame->pts != AV_NOPTS_VALUE )
         {
@@ -1140,7 +1148,7 @@ static block_t *EncodeVideo( encoder_t *p_enc, picture_t *p_pict )
     }
 
     block_t *p_block = vlc_av_packet_Wrap( &av_pkt,
-            av_pkt.duration / p_sys->p_context->time_base.den );
+            av_pkt.duration / p_sys->p_context->time_base.den, p_sys->p_context );
     if( unlikely(p_block == NULL) )
     {
         av_free_packet( &av_pkt );