From 1237e666afa70d2ad99cdd7d1d997cff73b341e3 Mon Sep 17 00:00:00 2001
From: Francois Cartegnie <fcvlcdev@free.fr>
Date: Tue, 19 Sep 2017 18:38:26 +0200
Subject: [PATCH] codec: cc: rework demux loop to remove local storage

---
 modules/codec/cc.c | 88 +++++++++++++++++++-----------------------------------
 1 file changed, 30 insertions(+), 58 deletions(-)

diff --git a/modules/codec/cc.c b/modules/codec/cc.c
index 34c02fde51..ae1ed13997 100644
--- a/modules/codec/cc.c
+++ b/modules/codec/cc.c
@@ -214,12 +214,9 @@ struct decoder_sys_t
     int      i_queue;
     block_t *p_queue;
 
-    block_t *p_block; /* currently processed block (if incomplely) */
-
     int i_field;
     int i_channel;
 
-    mtime_t i_display_time;
     int i_reorder_depth;
 
     eia608_t eia608;
@@ -290,16 +287,10 @@ static void Flush( decoder_t *p_dec )
     decoder_sys_t *p_sys = p_dec->p_sys;
 
     Eia608Init( &p_sys->eia608 );
-    p_sys->i_display_time = VLC_TS_INVALID;
 
     block_ChainRelease( p_sys->p_queue );
     p_sys->p_queue = NULL;
     p_sys->i_queue = 0;
-    if( p_sys->p_block )
-    {
-        block_Release( p_sys->p_block );
-        p_sys->p_block = NULL;
-    }
 }
 
 /****************************************************************************
@@ -309,20 +300,16 @@ static void Flush( decoder_t *p_dec )
  ****************************************************************************/
 static void     Push( decoder_t *, block_t * );
 static block_t *Pop( decoder_t *, bool );
-static subpicture_t *Convert( decoder_t *, block_t ** );
+static void     Convert( decoder_t *, mtime_t, const uint8_t *, size_t );
 
 static bool DoDecode( decoder_t *p_dec, bool b_drain )
 {
-    decoder_sys_t *p_sys = p_dec->p_sys;
-
-    if( !p_sys->p_block )
-        p_sys->p_block = Pop( p_dec, b_drain );
-    if( !p_sys->p_block )
+    block_t *p_block = Pop( p_dec, b_drain );
+    if( !p_block )
         return false;
 
-    subpicture_t *p_spu = Convert( p_dec, &p_sys->p_block );
-    if( p_spu )
-        decoder_QueueSub( p_dec, p_spu );
+    Convert( p_dec, p_block->i_pts, p_block->p_buffer, p_block->i_buffer );
+    block_Release( p_block );
 
     return true;
 }
@@ -339,7 +326,7 @@ static int Decode( decoder_t *p_dec, block_t *p_block )
             /* Drain */
             for( ; DoDecode( p_dec, true ) ; );
             Eia608Init( &p_sys->eia608 );
-            p_sys->i_display_time = VLC_TS_INVALID;
+
             if( (p_block->i_flags & BLOCK_FLAG_CORRUPTED) || p_block->i_buffer < 1 )
             {
                 block_Release( p_block );
@@ -483,54 +470,39 @@ static subpicture_t *Subtitle( decoder_t *p_dec, eia608_t *h, mtime_t i_pts )
     return p_spu;
 }
 
-static subpicture_t *Convert( decoder_t *p_dec, block_t **pp_block )
+static void Convert( decoder_t *p_dec, mtime_t i_pts,
+                     const uint8_t *p_buffer, size_t i_buffer )
 {
-    assert( pp_block && *pp_block );
-
-    block_t *p_block = *pp_block;
-
     decoder_sys_t *p_sys = p_dec->p_sys;
 
-    if( p_sys->i_display_time == VLC_TS_INVALID )
-        p_sys->i_display_time = p_block->i_pts;
-
-    eia608_status_t i_status = EIA608_STATUS_DEFAULT;
-
-    /* TODO do the real decoding here */
-    while( p_block->i_buffer >= 3 && !(i_status & EIA608_STATUS_DISPLAY) )
+    size_t i_ticks = 0;
+    while( i_buffer >= 3 )
     {
         /* Mask off the specific i_field bit, else some sequences can be lost. */
-        if ( (p_block->p_buffer[0] & 0x03) == p_sys->i_field &&
-             (p_block->p_buffer[0] & 0x04) /* Valid bit */ )
+        if ( (p_buffer[0] & 0x03) == p_sys->i_field &&
+             (p_buffer[0] & 0x04) /* Valid bit */ )
         {
-            i_status = Eia608Parse( &p_sys->eia608, p_sys->i_channel, &p_block->p_buffer[1] );
-            p_sys->i_display_time += CLOCK_FREQ / 30;
+            eia608_status_t i_status =
+                    Eia608Parse( &p_sys->eia608, p_sys->i_channel, &p_buffer[1] );
+
+            /* a caption is ready or removed, process its screen */
+            /*
+             * In case of rollup/painton with 1 packet/frame, we need to update on Changed status.
+             * Batch decoding might be incorrect if those in large number of commands (mp4, ...) then.
+             * see CEAv1.2zero.trp tests
+             */
+            if( i_status & (EIA608_STATUS_DISPLAY | EIA608_STATUS_CHANGED) )
+            {
+                subpicture_t *p_spu = Subtitle( p_dec, &p_sys->eia608, i_pts + i_ticks * CLOCK_FREQ / 30 );
+                if( p_spu )
+                    decoder_QueueSub( p_dec, p_spu );
+            }
         }
+        i_ticks++;
 
-        p_block->i_buffer -= 3;
-        p_block->p_buffer += 3;
-    }
-
-    const mtime_t i_pts = p_sys->i_display_time;
-
-    if( p_block->i_buffer < 3 )
-    {
-        block_Release( p_block );
-        p_sys->i_display_time = VLC_TS_INVALID;
-        *pp_block = NULL;
-    }
-
-    /* a caption is ready or removed, process its screen */
-    /*
-     * In case of rollup/painton with 1 packet/frame, we need to update on Changed status.
-     * Batch decoding might be incorrect if those in large number of commands (mp4, ...) then.
-     * see CEAv1.2zero.trp tests
-     */
-    if( i_status & (EIA608_STATUS_DISPLAY | EIA608_STATUS_CHANGED) )
-    {
-        return Subtitle( p_dec, &p_sys->eia608, i_pts );
+        i_buffer -= 3;
+        p_buffer += 3;
     }
-    return NULL;
 }
 
 
-- 
2.11.4.GIT