]> git.sesse.net Git - vlc/blobdiff - modules/packetizer/mpeg4video.c
Qt: CaptureOpenPanel: check and prefill with usual devices
[vlc] / modules / packetizer / mpeg4video.c
index e2eda071bd0dd5f3431fe88c69d956434ce6900a..84946a5842c26aeeaba547f84d4a278ce9e357aa 100644 (file)
@@ -1,12 +1,12 @@
 /*****************************************************************************
  * mpeg4video.c: mpeg 4 video packetizer
  *****************************************************************************
- * Copyright (C) 2001, 2002 VideoLAN
- * $Id: mpeg4video.c,v 1.16 2003/11/18 20:15:38 fenrir Exp $
+ * Copyright (C) 2001-2006 the VideoLAN team
+ * $Id$
  *
- * Authors: Laurent Aimar <fenrir@via.ecp.fr>
+ * Authors: Gildas Bazin <gbazin@videolan.org>
+ *          Laurent Aimar <fenrir@via.ecp.fr>
  *          Eric Petit <titer@videolan.org>
- *          Gildas Bazin <gbazin@netcourrier.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  *****************************************************************************/
 
 /*****************************************************************************
  * Preamble
  *****************************************************************************/
-#include <stdlib.h>                                      /* malloc(), free() */
 
-#include <vlc/vlc.h>
-#include <vlc/decoder.h>
-#include <vlc/sout.h>
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <vlc_common.h>
+#include <vlc_plugin.h>
+#include <vlc_sout.h>
+#include <vlc_codec.h>
+#include <vlc_block.h>
 
-#include "vlc_bits.h"
+#include <vlc_bits.h>
+#include <vlc_block_helper.h>
+#include "packetizer_helper.h"
 
 /*****************************************************************************
  * Module descriptor
 static int  Open ( vlc_object_t * );
 static void Close( vlc_object_t * );
 
-vlc_module_begin();
-    set_description( _("MPEG4 Video packetizer") );
-    set_capability( "packetizer", 50 );
-    set_callbacks( Open, Close );
-vlc_module_end();
-
+vlc_module_begin ()
+    set_category( CAT_SOUT )
+    set_subcategory( SUBCAT_SOUT_PACKETIZER )
+    set_description( N_("MPEG4 video packetizer") )
+    set_capability( "packetizer", 50 )
+    set_callbacks( Open, Close )
+vlc_module_end ()
 
 /****************************************************************************
  * Local prototypes
  ****************************************************************************/
-static block_t *Packetize( decoder_t *, block_t ** );
-
 struct decoder_sys_t
 {
+    /*
+     * Input properties
+     */
+    packetizer_t packetizer;
+
     /*
      * Common properties
      */
-    mtime_t i_pts;
-    mtime_t i_dts;
+    mtime_t i_interpolated_pts;
+    mtime_t i_interpolated_dts;
+    mtime_t i_last_ref_pts;
+    mtime_t i_last_time_ref;
+    mtime_t i_time_ref;
+    mtime_t i_last_time;
+    mtime_t i_last_timeincr;
+
+    unsigned int i_flags;
+
+    int         i_fps_num;
+    int         i_fps_den;
+    int         i_last_incr;
+    int         i_last_incr_diff;
+
+    bool  b_frame;
+
+    /* Current frame being built */
+    block_t    *p_frame;
+    block_t    **pp_last;
+};
 
+static block_t *Packetize( decoder_t *, block_t ** );
 
-    vlc_bool_t  b_vop;
-    int         i_buffer;
-    int         i_buffer_size;
-    uint8_t     *p_buffer;
-};
+static void PacketizeReset( void *p_private, bool b_broken );
+static block_t *PacketizeParse( void *p_private, bool *pb_ts_used, block_t * );
+static int PacketizeValidate( void *p_private, block_t * );
 
-static int m4v_FindStartCode( uint8_t **pp_start, uint8_t *p_end );
-static int m4v_VOLParse( es_format_t *fmt, uint8_t *p_vol, int i_vol );
+static block_t *ParseMPEGBlock( decoder_t *, block_t * );
+static int ParseVOL( decoder_t *, es_format_t *, uint8_t *, int );
+static int ParseVOP( decoder_t *, block_t * );
+static int vlc_log2( unsigned int );
 
 #define VIDEO_OBJECT_MASK                       0x01f
 #define VIDEO_OBJECT_LAYER_MASK                 0x00f
@@ -90,6 +121,8 @@ static int m4v_VOLParse( es_format_t *fmt, uint8_t *p_vol, int i_vol );
 #define TEXTURE_SPATIAL_LAYER_START_CODE        0x1bf
 #define TEXTURE_SNR_LAYER_START_CODE            0x1c0
 
+static const uint8_t p_mp4v_startcode[3] = { 0x00, 0x00, 0x01 };
+
 /*****************************************************************************
  * Open: probe the packetizer and return score
  *****************************************************************************/
@@ -98,54 +131,40 @@ static int Open( vlc_object_t *p_this )
     decoder_t     *p_dec = (decoder_t*)p_this;
     decoder_sys_t *p_sys;
 
-    switch( p_dec->fmt_in.i_codec )
-    {
-        case VLC_FOURCC( 'm', '4', 's', '2'):
-        case VLC_FOURCC( 'M', '4', 'S', '2'):
-        case VLC_FOURCC( 'm', 'p', '4', 's'):
-        case VLC_FOURCC( 'M', 'P', '4', 'S'):
-        case VLC_FOURCC( 'm', 'p', '4', 'v'):
-        case VLC_FOURCC( 'D', 'I', 'V', 'X'):
-        case VLC_FOURCC( 'd', 'i', 'v', 'x'):
-        case VLC_FOURCC( 'X', 'V', 'I', 'D'):
-        case VLC_FOURCC( 'X', 'v', 'i', 'D'):
-        case VLC_FOURCC( 'x', 'v', 'i', 'd'):
-        case VLC_FOURCC( 'D', 'X', '5', '0'):
-        case VLC_FOURCC( 0x04, 0,   0,   0):
-        case VLC_FOURCC( '3', 'I', 'V', '2'):
-            break;
-
-        default:
-            return VLC_EGENERIC;
-    }
+    if( p_dec->fmt_in.i_codec != VLC_CODEC_MP4V )
+        return VLC_EGENERIC;
 
     /* Allocate the memory needed to store the decoder's structure */
     if( ( p_dec->p_sys = p_sys = malloc( sizeof(decoder_sys_t) ) ) == NULL )
-    {
-        msg_Err( p_dec, "out of memory" );
-        return VLC_EGENERIC;
-    }
-    p_sys->i_pts = 0;
-    p_sys->b_vop = VLC_FALSE;
-    p_sys->i_buffer = 0;
-    p_sys->i_buffer_size = 10000;
-    p_sys->p_buffer = malloc( p_sys->i_buffer_size );
+        return VLC_ENOMEM;
+    memset( p_sys, 0, sizeof(decoder_sys_t) );
+
+    /* Misc init */
+    packetizer_Init( &p_sys->packetizer,
+                     p_mp4v_startcode, sizeof(p_mp4v_startcode),
+                     NULL, 0, 4,
+                     PacketizeReset, PacketizeParse, PacketizeValidate, p_dec );
+
+    p_sys->p_frame = NULL;
+    p_sys->pp_last = &p_sys->p_frame;
 
     /* Setup properties */
-    p_dec->fmt_out = p_dec->fmt_in;
-    p_dec->fmt_out.i_codec = VLC_FOURCC( 'm', 'p', '4', 'v' );
+    es_format_Copy( &p_dec->fmt_out, &p_dec->fmt_in );
+    p_dec->fmt_out.i_codec = VLC_CODEC_MP4V;
+
+    free(p_dec->fmt_out.p_extra);
 
     if( p_dec->fmt_in.i_extra )
     {
         /* We have a vol */
         p_dec->fmt_out.i_extra = p_dec->fmt_in.i_extra;
-        p_dec->fmt_out.p_extra = malloc( p_dec->fmt_in.i_extra );
+        p_dec->fmt_out.p_extra = xmalloc( p_dec->fmt_in.i_extra );
         memcpy( p_dec->fmt_out.p_extra, p_dec->fmt_in.p_extra,
                 p_dec->fmt_in.i_extra );
 
-        msg_Dbg( p_dec, "opening with vol size:%d", p_dec->fmt_in.i_extra );
-        m4v_VOLParse( &p_dec->fmt_out,
-                      p_dec->fmt_out.p_extra, p_dec->fmt_out.i_extra );
+        msg_Dbg( p_dec, "opening with vol size: %d", p_dec->fmt_in.i_extra );
+        ParseVOL( p_dec, &p_dec->fmt_out,
+                  p_dec->fmt_out.p_extra, p_dec->fmt_out.i_extra );
     }
     else
     {
@@ -166,8 +185,12 @@ static int Open( vlc_object_t *p_this )
 static void Close( vlc_object_t *p_this )
 {
     decoder_t *p_dec = (decoder_t*)p_this;
+    decoder_sys_t *p_sys = p_dec->p_sys;
 
-    free( p_dec->p_sys );
+    packetizer_Clean( &p_sys->packetizer );
+    if( p_sys->p_frame )
+        block_ChainRelease( p_sys->p_frame );
+    free( p_sys );
 }
 
 /****************************************************************************
@@ -177,196 +200,163 @@ static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
 {
     decoder_sys_t *p_sys = p_dec->p_sys;
 
-    block_t *p_chain_out = NULL;
-    block_t *p_block;
-    uint8_t *p_vol = NULL;
-    uint8_t *p_start;
-
-    if( !pp_block || !*pp_block ) return NULL;
+    return packetizer_Packetize( &p_sys->packetizer, pp_block );
+}
 
-    p_block = *pp_block;
+/*****************************************************************************
+ * Helpers:
+ *****************************************************************************/
+static void PacketizeReset( void *p_private, bool b_broken )
+{
+    decoder_t *p_dec = p_private;
+    decoder_sys_t *p_sys = p_dec->p_sys;
 
-    /* Append data */
-    if( p_sys->i_buffer + p_block->i_buffer > p_sys->i_buffer_size )
+    if( b_broken )
     {
-        p_sys->i_buffer_size += p_block->i_buffer + 1024;
-        p_sys->p_buffer = realloc( p_sys->p_buffer, p_sys->i_buffer_size );
+        if( p_sys->p_frame )
+            block_ChainRelease( p_sys->p_frame );
+        p_sys->p_frame = NULL;
+        p_sys->pp_last = &p_sys->p_frame;
     }
-    memcpy( &p_sys->p_buffer[p_sys->i_buffer], p_block->p_buffer,
-            p_block->i_buffer );
-    p_sys->i_buffer += p_block->i_buffer;
 
-    if( p_sys->i_buffer > 10*1000000 )
-    {
-        msg_Err( p_dec, "mmh reseting context" );
-        p_sys->i_buffer = 0;
-    }
+    p_sys->i_interpolated_pts =
+    p_sys->i_interpolated_dts =
+    p_sys->i_last_ref_pts = VLC_TS_INVALID;
 
-    /* Search vop */
-    p_start = &p_sys->p_buffer[p_sys->i_buffer - p_block->i_buffer - 4];
-    if( p_start < p_sys->p_buffer )
-    {
-        p_start = p_sys->p_buffer;
-    }
-    for( ;; )
-    {
-        if( m4v_FindStartCode( &p_start, &p_sys->p_buffer[p_sys->i_buffer] ) )
-        {
-            block_Release( p_block );
-            *pp_block = NULL;
-            return p_chain_out;
-        }
-        /* fprintf( stderr, "start code=0x1%2.2x\n", p_start[3] ); */
+    p_sys->i_last_time_ref =
+    p_sys->i_time_ref =
+    p_sys->i_last_time =
+    p_sys->i_last_timeincr = 0;
+}
 
-        if( p_vol )
-        {
-            /* Copy the complete VOL */
-            p_dec->fmt_out.i_extra = p_start - p_vol;
-            p_dec->fmt_out.p_extra = malloc( p_dec->fmt_out.i_extra );
-            memcpy( p_dec->fmt_out.p_extra, p_vol, p_dec->fmt_out.i_extra );
-            m4v_VOLParse( &p_dec->fmt_out,
-                          p_dec->fmt_out.p_extra, p_dec->fmt_out.i_extra );
-
-            p_vol = NULL;
-        }
-        if( p_sys->b_vop )
-        {
-            /* Output the complete VOP we have */
-            int     i_out = p_start - p_sys->p_buffer;
-            block_t *p_out = block_New( p_dec, i_out );
-
-            /* extract data */
-            memcpy( p_out->p_buffer, p_sys->p_buffer, i_out );
-            if( i_out < p_sys->i_buffer )
-            {
-                memmove( p_sys->p_buffer, &p_sys->p_buffer[i_out],
-                         p_sys->i_buffer - i_out );
-            }
-            p_sys->i_buffer -= i_out;
-            p_start -= i_out;
-
-            /* FIXME do proper dts/pts */
-            p_out->i_pts = p_sys->i_pts;
-            p_out->i_dts = p_sys->i_dts;
-            /* FIXME doesn't work when there is multiple VOP in one block */
-            if( p_block->i_dts > p_sys->i_dts )
-            {
-                p_out->i_length = p_block->i_dts - p_sys->i_dts;
-            }
-
-            if( p_dec->fmt_out.i_extra > 0 )
-            {
-                block_ChainAppend( &p_chain_out, p_out );
-            }
-            else
-            {
-                msg_Warn( p_dec, "waiting for VOL" );
-                block_Release( p_out );
-            }
+static block_t *PacketizeParse( void *p_private, bool *pb_ts_used, block_t *p_block )
+{
+    decoder_t *p_dec = p_private;
+    const mtime_t i_dts = p_block->i_dts;
+    const mtime_t i_pts = p_block->i_pts;
 
-#if 0
-            fprintf( stderr, "pts=%lld dts=%lld length=%lldms\n",
-                     p_out->i_pts, p_out->i_dts,
-                     p_out->i_length / 1000 );
-#endif
-            p_sys->b_vop = VLC_FALSE;
-        }
+    block_t *p_au = ParseMPEGBlock( p_dec, p_block );
 
-        if( p_start[3] >= 0x20 && p_start[3] <= 0x2f )
-        {
-            /* Start of the VOL */
-            p_vol = p_start;
-        }
-        else if( p_start[3] == 0xb6 )
-        {
-            p_sys->b_vop = VLC_TRUE;
-            p_sys->i_pts = p_block->i_pts;
-            p_sys->i_dts = p_block->i_dts;
-        }
-        p_start += 4; /* Next */
-    }
+    *pb_ts_used = p_au &&  p_au->i_dts == i_dts && p_au->i_pts == i_pts;
+
+    return p_au;
 }
 
-/****************************************************************************
- * m4v_FindStartCode
- ****************************************************************************/
-static int m4v_FindStartCode( uint8_t **pp_start, uint8_t *p_end )
+
+static int PacketizeValidate( void *p_private, block_t *p_au )
 {
-    uint8_t *p = *pp_start;
+    decoder_t *p_dec = p_private;
+    decoder_sys_t *p_sys = p_dec->p_sys;
 
-    for( p = *pp_start; p < p_end - 4; p++ )
+    /* We've just started the stream, wait for the first PTS.
+     * We discard here so we can still get the sequence header. */
+    if( p_sys->i_interpolated_pts <= VLC_TS_INVALID &&
+        p_sys->i_interpolated_dts <= VLC_TS_INVALID )
     {
-        if( p[0] == 0 && p[1] == 0 && p[2] == 1 )
-        {
-            *pp_start = p;
-            return VLC_SUCCESS;
-        }
+        msg_Dbg( p_dec, "need a starting pts/dts" );
+        return VLC_EGENERIC;
     }
 
-    *pp_start = p_end;
-    return VLC_EGENERIC;
+    /* When starting the stream we can have the first frame with
+     * a null DTS (i_interpolated_pts is initialized to 0) */
+    if( !p_au->i_dts )
+        p_au->i_dts = p_au->i_pts;
+    return VLC_SUCCESS;
 }
 
-
-/* look at ffmpeg av_log2 ;) */
-static int vlc_log2( unsigned int v )
+/*****************************************************************************
+ * ParseMPEGBlock: Re-assemble fragments into a block containing a picture
+ *****************************************************************************/
+static block_t *ParseMPEGBlock( decoder_t *p_dec, block_t *p_frag )
 {
-    int n = 0;
-    static const int vlc_log2_table[16] =
-    {
-        0,0,1,1,2,2,2,2, 3,3,3,3,3,3,3,3
-    };
+    decoder_sys_t *p_sys = p_dec->p_sys;
+    block_t *p_pic = NULL;
 
-    if( v&0xffff0000 )
+    if( p_frag->p_buffer[3] == 0xB0 || p_frag->p_buffer[3] == 0xB1 || p_frag->p_buffer[3] == 0xB2 )
+    {   /* VOS and USERDATA */
+#if 0
+        /* Remove VOS start/end code from the original stream */
+        block_Release( p_frag );
+#else
+        /* Append the block for now since ts/ps muxers rely on VOL
+         * being present in the stream */
+        block_ChainLastAppend( &p_sys->pp_last, p_frag );
+#endif
+        return NULL;
+    }
+    if( p_frag->p_buffer[3] >= 0x20 && p_frag->p_buffer[3] <= 0x2f )
     {
-        v >>= 16;
-        n += 16;
+        /* Copy the complete VOL */
+        if( (size_t)p_dec->fmt_out.i_extra != p_frag->i_buffer )
+        {
+            p_dec->fmt_out.p_extra =
+                xrealloc( p_dec->fmt_out.p_extra, p_frag->i_buffer );
+            p_dec->fmt_out.i_extra = p_frag->i_buffer;
+        }
+        memcpy( p_dec->fmt_out.p_extra, p_frag->p_buffer, p_frag->i_buffer );
+        ParseVOL( p_dec, &p_dec->fmt_out,
+                  p_dec->fmt_out.p_extra, p_dec->fmt_out.i_extra );
+
+#if 0
+        /* Remove from the original stream */
+        block_Release( p_frag );
+#else
+        /* Append the block for now since ts/ps muxers rely on VOL
+         * being present in the stream */
+        block_ChainLastAppend( &p_sys->pp_last, p_frag );
+#endif
+        return NULL;
     }
-    if( v&0xff00 )
+    else
     {
-        v >>= 8;
-        n += 8;
+        if( !p_dec->fmt_out.i_extra )
+        {
+            msg_Warn( p_dec, "waiting for VOL" );
+            block_Release( p_frag );
+            return NULL;
+        }
+
+        /* Append the block */
+        block_ChainLastAppend( &p_sys->pp_last, p_frag );
     }
-    if( v&0xf0 )
+
+    if( p_frag->p_buffer[3] == 0xb6 &&
+        ParseVOP( p_dec, p_frag ) == VLC_SUCCESS )
     {
-        v >>= 4;
-        n += 4;
+        /* We are dealing with a VOP */
+        p_pic = block_ChainGather( p_sys->p_frame );
+        p_pic->i_flags = p_sys->i_flags;
+        p_pic->i_pts = p_sys->i_interpolated_pts;
+        p_pic->i_dts = p_sys->i_interpolated_dts;
+
+        /* Reset context */
+        p_sys->p_frame = NULL;
+        p_sys->pp_last = &p_sys->p_frame;
     }
-    n += vlc_log2_table[v];
 
-    return n;
+    return p_pic;
 }
 
-/* m4v_VOLParse:
+/* ParseVOL:
  *  TODO:
  *      - support aspect ratio
  */
-static int m4v_VOLParse( es_format_t *fmt, uint8_t *p_vol, int i_vol )
+static int ParseVOL( decoder_t *p_dec, es_format_t *fmt,
+                     uint8_t *p_vol, int i_vol )
 {
+    decoder_sys_t *p_sys = p_dec->p_sys;
+    int i_vo_type, i_vo_ver_id, i_ar, i_shape;
     bs_t s;
-    int i_vo_type;
-    int i_vo_ver_id;
-    int i_ar;
-    int i_shape;
-    int i_time_increment_resolution;
 
     for( ;; )
     {
-        if( p_vol[0] == 0x00 && p_vol[1] == 0x00 &&
-            p_vol[2] == 0x01 &&
-            p_vol[3] >= 0x20 && p_vol[3] <= 0x2f )
-        {
-            break;
-        }
-        p_vol++;
-        i_vol--;
-        if( i_vol <= 4 )
-        {
-            return VLC_EGENERIC;
-        }
+        if( p_vol[0] == 0x00 && p_vol[1] == 0x00 && p_vol[2] == 0x01 &&
+            p_vol[3] >= 0x20 && p_vol[3] <= 0x2f ) break;
+
+        p_vol++; i_vol--;
+        if( i_vol <= 4 ) return VLC_EGENERIC;
     }
 
-    /* parse the vol */
     bs_init( &s, &p_vol[4], i_vol - 4 );
 
     bs_skip( &s, 1 );   /* random access */
@@ -383,14 +373,19 @@ static int m4v_VOLParse( es_format_t *fmt, uint8_t *p_vol, int i_vol )
     i_ar = bs_read( &s, 4 );
     if( i_ar == 0xf )
     {
-        int i_ar_width = bs_read( &s, 8 );
-        int i_ar_height= bs_read( &s, 8 );
+        int i_ar_width, i_ar_height;
+
+        i_ar_width = bs_read( &s, 8 );
+        i_ar_height= bs_read( &s, 8 );
     }
     if( bs_read1( &s ) )
     {
+        int i_chroma_format;
+        int i_low_delay;
+
         /* vol control parameter */
-        int i_chroma_format = bs_read( &s, 2 );
-        int i_low_delay = bs_read1( &s );
+        i_chroma_format = bs_read( &s, 2 );
+        i_low_delay = bs_read1( &s );
 
         if( bs_read1( &s ) )
         {
@@ -410,26 +405,20 @@ static int m4v_VOLParse( es_format_t *fmt, uint8_t *p_vol, int i_vol )
         bs_skip( &s, 4 );
     }
 
-    if( !bs_read1( &s ) )
-    {
-        /* marker */
-        return VLC_EGENERIC;
-    }
-    i_time_increment_resolution = bs_read( &s, 16 );
-    if( !bs_read1( &s ) )
-    {
-        /* marker */
-        return VLC_EGENERIC;
-    }
+    if( !bs_read1( &s ) ) return VLC_EGENERIC; /* Marker */
+
+    p_sys->i_fps_num = bs_read( &s, 16 ); /* Time increment resolution*/
+    if( !p_sys->i_fps_num ) p_sys->i_fps_num = 1;
+
+    if( !bs_read1( &s ) ) return VLC_EGENERIC; /* Marker */
 
     if( bs_read1( &s ) )
     {
-        int i_time_increment_bits = vlc_log2( i_time_increment_resolution - 1 ) + 1;
-        if( i_time_increment_bits < 1 )
-        {
-            i_time_increment_bits = 1;
-        }
-        bs_skip( &s, i_time_increment_bits );
+        int i_time_increment_bits = vlc_log2( p_sys->i_fps_num - 1 ) + 1;
+
+        if( i_time_increment_bits < 1 ) i_time_increment_bits = 1;
+
+        p_sys->i_fps_den = bs_read( &s, i_time_increment_bits );
     }
     if( i_shape == 0 )
     {
@@ -439,8 +428,136 @@ static int m4v_VOLParse( es_format_t *fmt, uint8_t *p_vol, int i_vol )
         fmt->video.i_height= bs_read( &s, 13 );
         bs_skip( &s, 1 );
     }
+
     return VLC_SUCCESS;
 }
 
+static int ParseVOP( decoder_t *p_dec, block_t *p_vop )
+{
+    decoder_sys_t *p_sys = p_dec->p_sys;
+    int64_t i_time_increment, i_time_ref;
+    int i_modulo_time_base = 0, i_time_increment_bits;
+    bs_t s;
+
+    bs_init( &s, &p_vop->p_buffer[4], p_vop->i_buffer - 4 );
+
+    switch( bs_read( &s, 2 ) )
+    {
+    case 0:
+        p_sys->i_flags = BLOCK_FLAG_TYPE_I;
+        break;
+    case 1:
+        p_sys->i_flags = BLOCK_FLAG_TYPE_P;
+        break;
+    case 2:
+        p_sys->i_flags = BLOCK_FLAG_TYPE_B;
+        p_sys->b_frame = true;
+        break;
+    case 3: /* gni ? */
+        p_sys->i_flags = BLOCK_FLAG_TYPE_PB;
+        break;
+    }
+
+    while( bs_read( &s, 1 ) ) i_modulo_time_base++;
+    if( !bs_read1( &s ) ) return VLC_EGENERIC; /* Marker */
+
+    /* VOP time increment */
+    i_time_increment_bits = vlc_log2(p_dec->p_sys->i_fps_num - 1) + 1;
+    if( i_time_increment_bits < 1 ) i_time_increment_bits = 1;
+    i_time_increment = bs_read( &s, i_time_increment_bits );
 
+    /* Interpolate PTS/DTS */
+    if( !(p_sys->i_flags & BLOCK_FLAG_TYPE_B) )
+    {
+        p_sys->i_last_time_ref = p_sys->i_time_ref;
+        p_sys->i_time_ref +=
+            (i_modulo_time_base * p_dec->p_sys->i_fps_num);
+        i_time_ref = p_sys->i_time_ref;
+    }
+    else
+    {
+        i_time_ref = p_sys->i_last_time_ref +
+            (i_modulo_time_base * p_dec->p_sys->i_fps_num);
+    }
+
+#if 0
+    msg_Err( p_dec, "interp pts/dts (%lli,%lli), pts/dts (%lli,%lli)",
+             p_sys->i_interpolated_pts, p_sys->i_interpolated_dts,
+             p_vop->i_pts, p_vop->i_dts );
+#endif
 
+    if( p_dec->p_sys->i_fps_num < 5 && /* Work-around buggy streams */
+        p_dec->fmt_in.video.i_frame_rate > 0 &&
+        p_dec->fmt_in.video.i_frame_rate_base > 0 )
+    {
+        p_sys->i_interpolated_pts += INT64_C(1000000) *
+        p_dec->fmt_in.video.i_frame_rate_base /
+        p_dec->fmt_in.video.i_frame_rate;
+    }
+    else if( p_dec->p_sys->i_fps_num )
+        p_sys->i_interpolated_pts +=
+            ( INT64_C(1000000) * (i_time_ref + i_time_increment -
+              p_sys->i_last_time - p_sys->i_last_timeincr) /
+              p_dec->p_sys->i_fps_num );
+
+    p_sys->i_last_time = i_time_ref;
+    p_sys->i_last_timeincr = i_time_increment;
+
+    /* Correct interpolated dts when we receive a new pts/dts */
+    if( p_vop->i_pts > VLC_TS_INVALID )
+        p_sys->i_interpolated_pts = p_vop->i_pts;
+    if( p_vop->i_dts > VLC_TS_INVALID )
+        p_sys->i_interpolated_dts = p_vop->i_dts;
+
+    if( (p_sys->i_flags & BLOCK_FLAG_TYPE_B) || !p_sys->b_frame )
+    {
+        /* Trivial case (DTS == PTS) */
+
+        p_sys->i_interpolated_dts = p_sys->i_interpolated_pts;
+
+        if( p_vop->i_pts > VLC_TS_INVALID )
+            p_sys->i_interpolated_dts = p_vop->i_pts;
+        if( p_vop->i_dts > VLC_TS_INVALID )
+            p_sys->i_interpolated_dts = p_vop->i_dts;
+
+        p_sys->i_interpolated_pts = p_sys->i_interpolated_dts;
+    }
+    else
+    {
+        if( p_sys->i_last_ref_pts > VLC_TS_INVALID )
+            p_sys->i_interpolated_dts = p_sys->i_last_ref_pts;
+
+        p_sys->i_last_ref_pts = p_sys->i_interpolated_pts;
+    }
+
+    return VLC_SUCCESS;
+}
+
+/* look at ffmpeg av_log2 ;) */
+static int vlc_log2( unsigned int v )
+{
+    int n = 0;
+    static const int vlc_log2_table[16] =
+    {
+        0,0,1,1,2,2,2,2, 3,3,3,3,3,3,3,3
+    };
+
+    if( v&0xffff0000 )
+    {
+        v >>= 16;
+        n += 16;
+    }
+    if( v&0xff00 )
+    {
+        v >>= 8;
+        n += 8;
+    }
+    if( v&0xf0 )
+    {
+        v >>= 4;
+        n += 4;
+    }
+    n += vlc_log2_table[v];
+
+    return n;
+}