decavsub: use libav to decode dvd subtitles

Simplifies code, removes encvobsub.c (was never used) and decvobsub.c.

12 files changed, 154 insertions, 858 deletions

diff --git a/contrib/ffmpeg/A14-dvdsubdec-fix-processing-of-partial-packets.patch b/contrib/ffmpeg/A14-dvdsubdec-fix-processing-of-partial-packets.patch
new file mode 100644
index 000000000..dbe1d8d7c
--- /dev/null
+++ b/contrib/ffmpeg/A14-dvdsubdec-fix-processing-of-partial-packets.patch
@@ -0,0 +1,49 @@
+From b5846bbdf2bea0ec40ab68fbb5440e17a9390f65 Mon Sep 17 00:00:00 2001
+From: John Stebbins <[email protected]>
+Date: Wed, 11 Dec 2019 14:10:09 -0800
+Subject: [PATCH] dvdsubdec: fix processing of partial packets
+
+Wait for a complete dvd subtitle before processing.
+
+If the input packet is large enough to start processing, but does not
+contain complete data, unfinished results are emitted and the following
+input packet causes an error because the stream is no longer in sync
+with the decoder.
+---
+ libavcodec/dvdsubdec.c | 12 ++++++------
+ 1 file changed, 6 insertions(+), 6 deletions(-)
+
+diff --git a/libavcodec/dvdsubdec.c b/libavcodec/dvdsubdec.c
+index 741ea9fd1e..c0c9962bad 100644
+--- a/libavcodec/dvdsubdec.c
++++ b/libavcodec/dvdsubdec.c
+@@ -232,7 +232,7 @@ static int decode_dvd_subtitles(DVDSubContext *ctx, AVSubtitle *sub_header,
+     int64_t offset1, offset2;
+ 
+     if (buf_size < 10)
+-        return -1;
++        return AVERROR(EAGAIN);
+ 
+     if (AV_RB16(buf) == 0) {   /* HD subpicture with 4-byte offsets */
+         big_offsets = 1;
+@@ -247,12 +247,12 @@ static int decode_dvd_subtitles(DVDSubContext *ctx, AVSubtitle *sub_header,
+     size = READ_OFFSET(buf + (big_offsets ? 2 : 0));
+     cmd_pos = READ_OFFSET(buf + cmd_pos);
+ 
+-    if (cmd_pos < 0 || cmd_pos > buf_size - 2 - offset_size) {
+-        if (cmd_pos > size) {
+-            av_log(ctx, AV_LOG_ERROR, "Discarding invalid packet\n");
+-            return 0;
+-        }
++    if (buf_size < size)
+         return AVERROR(EAGAIN);
++
++    if (cmd_pos < 0 || cmd_pos > size) {
++        av_log(ctx, AV_LOG_ERROR, "Discarding invalid packet\n");
++        return AVERROR_INVALIDDATA;
+     }
+ 
+     while (cmd_pos > 0 && cmd_pos < buf_size - 2 - offset_size) {
+-- 
+2.23.0
+
diff --git a/libhb/decavsub.c b/libhb/decavsub.c
index 71baaf3a3..27e94099c 100644
--- a/libhb/decavsub.c
+++ b/libhb/decavsub.c
@@ -23,6 +23,20 @@ struct hb_avsub_context_s
     hb_buffer_list_t list_pass;
     // List of subtitle packets to be output by this decoder.
     hb_buffer_list_t list;
+    // DVD subtitles: ffmpeg returns the timestamp of the last packet
+    // submitted when a DVD subtitle spans multiple packets.  So we must
+    // keep track of the start time of the first packet. In this case
+    // sub_pts is reset when ffmpeg delivers us a subtitle.
+    //
+    // BUT, EIA 608 can have many nil packets before the actual subtitle
+    // begins and the ffmpeg decoder keeps track of the timestamp where
+    // the subtitle actually begins for us. In this case sub_pts must be
+    // reset for every packet.  I.e. the opposite of what we have to do for
+    // DVD subtitle :(
+    //
+    // PGS subtitles should also reset this for each packet since the packet
+    // with the presentation segment defines the display time.
+    int64_t sub_pts;
     // XXX: we may occasionally see subtitles with broken timestamps
     //      while this should really get fixed elsewhere,
     //      dropping subtitles should be avoided as much as possible
@@ -48,6 +62,7 @@ hb_avsub_context_t * decavsubInit( hb_work_object_t * w, hb_job_t * job )
     }
     ctx->seen_forced_sub       = 0;
     ctx->last_pts              = AV_NOPTS_VALUE;
+    ctx->sub_pts               = AV_NOPTS_VALUE;
     ctx->job                   = job;
     ctx->subtitle              = w->subtitle;
 
@@ -69,6 +84,29 @@ hb_avsub_context_t * decavsubInit( hb_work_object_t * w, hb_job_t * job )
     {
         av_dict_set( &av_opts, "real_time", "1", 0 );
     }
+    if (ctx->subtitle->source == VOBSUB && ctx->subtitle->palette_set)
+    {
+        char * palette = hb_strdup_printf(
+            "%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x",
+            hb_yuv2rgb(ctx->subtitle->palette[0]),
+            hb_yuv2rgb(ctx->subtitle->palette[1]),
+            hb_yuv2rgb(ctx->subtitle->palette[2]),
+            hb_yuv2rgb(ctx->subtitle->palette[3]),
+            hb_yuv2rgb(ctx->subtitle->palette[4]),
+            hb_yuv2rgb(ctx->subtitle->palette[5]),
+            hb_yuv2rgb(ctx->subtitle->palette[6]),
+            hb_yuv2rgb(ctx->subtitle->palette[7]),
+            hb_yuv2rgb(ctx->subtitle->palette[8]),
+            hb_yuv2rgb(ctx->subtitle->palette[9]),
+            hb_yuv2rgb(ctx->subtitle->palette[10]),
+            hb_yuv2rgb(ctx->subtitle->palette[11]),
+            hb_yuv2rgb(ctx->subtitle->palette[12]),
+            hb_yuv2rgb(ctx->subtitle->palette[13]),
+            hb_yuv2rgb(ctx->subtitle->palette[14]),
+            hb_yuv2rgb(ctx->subtitle->palette[15]));
+        av_dict_set( &av_opts, "palette", palette, 0 );
+        free(palette);
+    }
 
     if (hb_avcodec_open(ctx->context, codec, &av_opts, 0))
     {
@@ -280,10 +318,14 @@ int decavsubWork( hb_avsub_context_t * ctx,
     int64_t duration = AV_NOPTS_VALUE;
     AVPacket avp;
 
+    if (ctx->sub_pts == AV_NOPTS_VALUE)
+    {
+        ctx->sub_pts = in->s.start;
+    }
     av_init_packet( &avp );
     avp.data = in->data;
     avp.size = in->size;
-    avp.pts  = in->s.start;
+    avp.pts  = ctx->sub_pts;
     duration = in->s.duration;
 
     if (duration <= 0 &&
@@ -305,6 +347,7 @@ int decavsubWork( hb_avsub_context_t * ctx,
             return HB_WORK_OK;
         }
 
+        // <UGLY_HACKS>
         // Ugly hack, but ffmpeg doesn't consume a trailing 0xff in
         // DVB subtitle buffers :(
         if (ctx->subtitle->source == DVBSUB &&
@@ -314,10 +357,23 @@ int decavsubWork( hb_avsub_context_t * ctx,
             usedBytes++;
         }
         // Another ugly hack, ffmpeg always returns 0 for CC decoder :(
-        if (ctx->subtitle->source == CC608SUB)
+        //
+        // Also returns 0 for DVD subtitles, until it emits an AVSubtitle,
+        // then it returns the total number of bytes used to construct
+        // that subtitle :(
+        if (ctx->subtitle->source == CC608SUB ||
+            ctx->subtitle->source == VOBSUB)
         {
             usedBytes = avp.size;
         }
+        // ffmpeg needs us to remember the timestamp of the first packet of
+        // DVD subtitles
+        if (ctx->subtitle->source != VOBSUB)
+        {
+            ctx->sub_pts = AV_NOPTS_VALUE;
+        }
+        // </UGLY_HACKS>
+
         if (usedBytes <= avp.size)
         {
             avp.data += usedBytes;
@@ -332,6 +388,7 @@ int decavsubWork( hb_avsub_context_t * ctx,
         {
             continue;
         }
+        ctx->sub_pts = AV_NOPTS_VALUE;
 
         uint8_t forced_sub = 0;
         uint8_t usable_sub = 0;
@@ -474,13 +531,6 @@ int decavsubWork( hb_avsub_context_t * ctx,
                 out = hb_buffer_init(0);
                 out->s.flags = HB_BUF_FLAG_EOS;
             }
-            out->s.frametype    = HB_FRAME_SUBTITLE;
-            out->s.start        = pts;
-            if (duration != AV_NOPTS_VALUE)
-            {
-                out->s.stop      = pts + duration;
-                out->s.duration  = duration;
-            }
             hb_buffer_list_close(&ctx->list_pass);
         }
         else if (ctx->subtitle->config.dest == PASSTHRUSUB &&
@@ -522,11 +572,11 @@ int decavsubWork( hb_avsub_context_t * ctx,
                     b = b->next;
                 }
                 hb_buffer_list_close(&ctx->list_pass);
-
-                out->s        = in->s;
             }
-            out->s.frametype    = HB_FRAME_SUBTITLE;
-            out->s.start        = pts;
+            if (clear_sub)
+            {
+                out->s.flags = HB_BUF_FLAG_EOS;
+            }
         }
         else
         {
@@ -558,10 +608,6 @@ int decavsubWork( hb_avsub_context_t * ctx,
                 out = hb_frame_buffer_init(AV_PIX_FMT_YUVA420P, w, h);
                 memset(out->data, 0, out->size);
 
-                out->s.frametype     = HB_FRAME_SUBTITLE;
-                out->s.id            = in->s.id;
-                out->s.start         = pts;
-                out->s.scr_sequence  = in->s.scr_sequence;
                 out->f.x             = x0;
                 out->f.y             = y0;
                 out->f.window_width  = ctx->context->width;
@@ -613,25 +659,29 @@ int decavsubWork( hb_avsub_context_t * ctx,
                         alpha += out->plane[3].stride;
                     }
                 }
-                hb_buffer_list_append(&ctx->list, out);
-                out = NULL;
             }
             else
             {
                 out = hb_buffer_init( 0 );
 
-                out->s.frametype    = HB_FRAME_SUBTITLE;
-                out->s.flags        = HB_BUF_FLAG_EOS;
-                out->s.id           = in->s.id;
-                out->s.start        = pts;
-                out->s.stop         = pts;
-                out->s.scr_sequence = in->s.scr_sequence;
-                out->f.x            = 0;
-                out->f.y            = 0;
-                out->f.width        = 0;
-                out->f.height       = 0;
+                out->s.flags  = HB_BUF_FLAG_EOS;
+                out->f.x      = 0;
+                out->f.y      = 0;
+                out->f.width  = 0;
+                out->f.height = 0;
+                duration      = 0;
             }
         }
+        out->s.id           = in->s.id;
+        out->s.scr_sequence = in->s.scr_sequence;
+        out->s.frametype    = HB_FRAME_SUBTITLE;
+        out->s.start        = pts;
+        if (duration != AV_NOPTS_VALUE)
+        {
+            out->s.stop      = pts + duration;
+            out->s.duration  = duration;
+        }
+
         hb_buffer_list_append(&ctx->list, out);
         avsubtitle_free(&subtitle);
     }
diff --git a/libhb/decvobsub.c b/libhb/decvobsub.c
deleted file mode 100644
index c8b5f149a..000000000
--- a/libhb/decvobsub.c
+++ /dev/null
@@ -1,734 +0,0 @@
-/* decvobsub.c
-
-   Copyright (c) 2003-2020 HandBrake Team
-   This file is part of the HandBrake source code
-   Homepage: <http://handbrake.fr/>.
-   It may be used under the terms of the GNU General Public License v2.
-   For full terms see the file COPYING file or visit http://www.gnu.org/licenses/gpl-2.0.html
- */
-
-/*
- * Decoder for DVD bitmap subtitles, also known as "VOB subtitles" within the HandBrake source code.
- *
- * Input format of the subtitle packets is described here:
- *   http://sam.zoy.org/writings/dvd/subtitles/
- *
- * An auxiliary input is the color palette lookup table, in 'subtitle->palette'.
- * The demuxer implementation must fill out this table appropriately.
- * - In the case of a true DVD input, the palette is read from the IFO file.
- * - In the case of an MKV file input, the palette is read from the codec private data of the subtitle track.
- *
- * Output format of this decoder is PICTURESUB, which is:
- *   struct PictureSubPacket {
- *       uint8_t lum[pixelCount];       // Y
- *       uint8_t alpha[pixelCount];     // alpha (max = 16)
- *       uint8_t chromaU[pixelCount];   // Cb
- *       uint8_t chromaV[pixelCount];   // Cr
- *   }
- */
-
-#include "handbrake/handbrake.h"
-
-struct hb_work_private_s
-{
-    hb_job_t    * job;
-
-    hb_buffer_t * buf;
-    int           size_sub;
-    int           size_got;
-    int           size_rle;
-    int64_t       pts;
-    int           current_scr_sequence;
-    int64_t       pts_start;
-    int64_t       pts_stop;
-    int           scr_sequence;
-    int           pts_forced;
-    int           x;
-    int           y;
-    int           width;
-    int           height;
-    int           stream_id;
-
-    int           offsets[2];
-    uint8_t       lum[4];
-    uint8_t       chromaU[4];
-    uint8_t       chromaV[4];
-    uint8_t       alpha[4];
-    uint8_t       palette_set;
-};
-
-static hb_buffer_t * Decode( hb_work_object_t * );
-
-int decsubInit( hb_work_object_t * w, hb_job_t * job )
-{
-    hb_work_private_t * pv;
-
-    pv              = calloc( 1, sizeof( hb_work_private_t ) );
-    w->private_data = pv;
-
-    pv->job = job;
-    pv->pts = 0;
-
-    // Warn if the input color palette is empty
-    pv->palette_set = w->subtitle->palette_set;
-    if ( pv->palette_set )
-    {
-        // Make sure the entries in the palette are not all 0
-        pv->palette_set = 0;
-        int i;
-        for (i=0; i<16; i++)
-        {
-            if (w->subtitle->palette[i])
-            {
-                pv->palette_set = 1;
-                break;
-            }
-        }
-    }
-    if (!pv->palette_set) {
-        hb_log( "decvobsub: input color palette is empty!" );
-    }
-
-    return 0;
-}
-
-int decsubWork( hb_work_object_t * w, hb_buffer_t ** buf_in,
-                hb_buffer_t ** buf_out )
-{
-    hb_work_private_t * pv = w->private_data;
-    hb_buffer_t * in = *buf_in;
-    int size_sub, size_rle;
-
-    if (in->s.flags & HB_BUF_FLAG_EOF)
-    {
-        /* EOF on input stream - send it downstream & say that we're done */
-        *buf_out = in;
-        *buf_in = NULL;
-        return HB_WORK_DONE;
-    }
-
-    pv->stream_id = in->s.id;
-
-    size_sub = ( in->data[0] << 8 ) | in->data[1];
-    size_rle = ( in->data[2] << 8 ) | in->data[3];
-
-    if( !pv->size_sub )
-    {
-        /* We are looking for the start of a new subtitle */
-        if( size_sub && size_rle && size_sub > size_rle &&
-            in->size <= size_sub )
-        {
-            /* Looks all right so far */
-            pv->size_sub = size_sub;
-            pv->size_rle = size_rle;
-
-            pv->buf      = hb_buffer_init( 0xFFFF );
-            memcpy( pv->buf->data, in->data, in->size );
-            pv->buf->s.id = in->s.id;
-            pv->buf->s.frametype = HB_FRAME_SUBTITLE;
-            pv->size_got = in->size;
-            if( in->s.start >= 0 )
-            {
-                pv->pts                  = in->s.start;
-                pv->current_scr_sequence = in->s.scr_sequence;
-            }
-        }
-    }
-    else
-    {
-        /* We are waiting for the end of the current subtitle */
-        if( in->size <= pv->size_sub - pv->size_got )
-        {
-            memcpy( pv->buf->data + pv->size_got, in->data, in->size );
-            pv->buf->s.id = in->s.id;
-            pv->size_got += in->size;
-            if( in->s.start >= 0 )
-            {
-                pv->pts                  = in->s.start;
-                pv->current_scr_sequence = in->s.scr_sequence;
-            }
-        }
-        else
-        {
-            // bad size, must have lost sync
-            // force re-sync
-            if ( pv->buf != NULL )
-                hb_buffer_close( &pv->buf );
-            pv->size_sub = 0;
-        }
-
-    }
-
-    *buf_out = NULL;
-
-    if( pv->size_sub && pv->size_sub == pv->size_got )
-    {
-        pv->buf->size = pv->size_sub;
-
-        /* We got a complete subtitle, decode it */
-        *buf_out = Decode( w );
-
-        if ( *buf_out != NULL )
-            (*buf_out)->s.id = in->s.id;
-
-        /* Wait for the next one */
-        pv->size_sub = 0;
-        pv->size_got = 0;
-        pv->size_rle = 0;
-
-        if ( pv->pts_stop != AV_NOPTS_VALUE )
-        {
-            // If we don't get a valid next timestamp, use the stop time
-            // of the current sub as the start of the next.
-            // This can happen if reader invalidates timestamps while
-            // waiting for an audio to update the SCR.
-            pv->pts                  = pv->pts_stop;
-            pv->current_scr_sequence = pv->scr_sequence;
-        }
-    }
-
-    return HB_WORK_OK;
-}
-
-void decsubClose( hb_work_object_t * w )
-{
-    hb_work_private_t * pv = w->private_data;
-
-    if ( pv && pv->buf )
-        hb_buffer_close( &pv->buf );
-    free( w->private_data );
-}
-
-hb_work_object_t hb_decvobsub =
-{
-    WORK_DECVOBSUB,
-    "VOBSUB decoder",
-    decsubInit,
-    decsubWork,
-    decsubClose
-};
-
-
-/***********************************************************************
- * ParseControls
- ***********************************************************************
- * Get the start and end dates (relative to the PTS from the PES
- * header), the width and height of the subpicture and the colors and
- * alphas used in it
- **********************************************************************/
-static int ParseControls( hb_work_object_t * w )
-{
-    hb_work_private_t * pv = w->private_data;
-    uint8_t * buf = pv->buf->data;
-
-    int i;
-    int command;
-    int date, next;
-
-    pv->pts_start = AV_NOPTS_VALUE;
-    pv->pts_stop  = AV_NOPTS_VALUE;
-    pv->pts_forced  = 0;
-
-    pv->alpha[3] = 0;
-    pv->alpha[2] = 0;
-    pv->alpha[1] = 0;
-    pv->alpha[0] = 0;
-
-    for( i = pv->size_rle; ; )
-    {
-        if ( i + 1 >= pv->buf->size )
-        {
-            return 1;
-        }
-
-        date = ( buf[i] << 8 ) | buf[i+1]; i += 2;
-        next = ( buf[i] << 8 ) | buf[i+1]; i += 2;
-
-        for( ;; )
-        {
-            if ( i >= pv->buf->size )
-            {
-                return 1;
-            }
-            command = buf[i++];
-
-            /*
-             * There are eight commands available for
-             * Sub-Pictures. The first SP_DCSQ should contain, as a
-             * minimum, SET_COLOR, SET_CONTR, SET_DAREA, and
-             * SET_DSPXA
-             */
-
-            if( command == 0xFF ) // 0xFF - CMD_END - ends one SP_DCSQ
-            {
-                break;
-            }
-
-            switch( command )
-            {
-                case 0x00: // 0x00 - FSTA_DSP - Forced Start Display, no arguments
-                    pv->pts_start    = pv->pts + date * 1024;
-                    pv->scr_sequence = pv->current_scr_sequence;
-                    pv->pts_forced   = 1;
-                    w->subtitle->hits++;
-                    w->subtitle->forced_hits++;
-                    break;
-
-                case 0x01: // 0x01 - STA_DSP - Start Display, no arguments
-                    pv->pts_start    = pv->pts + date * 1024;
-                    pv->scr_sequence = pv->current_scr_sequence;
-                    pv->pts_forced   = 0;
-                    w->subtitle->hits++;
-                    break;
-
-                case 0x02: // 0x02 - STP_DSP - Stop Display, no arguments
-                    if (pv->pts_stop == AV_NOPTS_VALUE)
-                    {
-                        pv->pts_stop     = pv->pts + date * 1024;
-                        pv->scr_sequence = pv->current_scr_sequence;
-                    }
-                    break;
-
-                case 0x03: // 0x03 - SET_COLOR - Set Colour indices
-                {
-                    /*
-                     * SET_COLOR - provides four indices into the CLUT
-                     * for the current PGC to associate with the four
-                     * pixel values
-                     */
-                    int colors[4];
-                    int j;
-
-                    if ( i + 1 >= pv->buf->size )
-                    {
-                        return 1;
-                    }
-
-                    colors[0] = (buf[i+0]>>4)&0x0f;
-                    colors[1] = (buf[i+0])&0x0f;
-                    colors[2] = (buf[i+1]>>4)&0x0f;
-                    colors[3] = (buf[i+1])&0x0f;
-
-                    for( j = 0; j < 4; j++ )
-                    {
-                        /*
-                         * Not sure what is happening here, in theory
-                         * the palette is in YCbCr. And we want YUV.
-                         *
-                         * However it looks more like YCrCb (according
-                         * to pgcedit). And the scalers for YCrCb don't
-                         * work, but I get the right colours by doing
-                         * no conversion.
-                         */
-                        uint32_t color = w->subtitle->palette[colors[j]];
-                        uint8_t Cr, Cb, y;
-                        y = (color>>16) & 0xff;
-                        Cr = (color>>8) & 0xff;
-                        Cb = (color) & 0xff;
-                        pv->lum[3-j] = y;
-                        pv->chromaU[3-j] = Cb;
-                        pv->chromaV[3-j] = Cr;
-                        /* hb_log("color[%d] y = %d, u = %d, v = %d",
-                               3-j,
-                               pv->lum[3-j],
-                               pv->chromaU[3-j],
-                               pv->chromaV[3-j]);
-                        */
-                    }
-                    i += 2;
-                    break;
-                }
-                case 0x04: // 0x04 - SET_CONTR - Set Contrast
-                {
-                    /*
-                     * SET_CONTR - directly provides the four contrast
-                     * (alpha blend) values to associate with the four
-                     * pixel values
-                     */
-                    uint8_t    alpha[4];
-
-                    if ( i + 1 >= pv->buf->size )
-                    {
-                        return 1;
-                    }
-
-                    alpha[3] = ((buf[i+0] >> 4) & 0x0f) << 4;
-                    alpha[2] = ((buf[i+0]     ) & 0x0f) << 4;
-                    alpha[1] = ((buf[i+1] >> 4) & 0x0f) << 4;
-                    alpha[0] = ((buf[i+1]     ) & 0x0f) << 4;
-
-
-                    int lastAlpha = pv->alpha[3] + pv->alpha[2] + pv->alpha[1] + pv->alpha[0];
-                    int currAlpha = alpha[3] + alpha[2] + alpha[1] + alpha[0];
-
-                    // fading-in, save the highest alpha value
-                    if( currAlpha > lastAlpha )
-                    {
-                        pv->alpha[3] = alpha[3];
-                        pv->alpha[2] = alpha[2];
-                        pv->alpha[1] = alpha[1];
-                        pv->alpha[0] = alpha[0];
-                    }
-
-                    // fading-out
-                    if (currAlpha < lastAlpha && pv->pts_stop == AV_NOPTS_VALUE)
-                    {
-                        pv->pts_stop     = pv->pts + date * 1024;
-                        pv->scr_sequence = pv->current_scr_sequence;
-                    }
-
-                    i += 2;
-                    break;
-                }
-                case 0x05: // 0x05 - SET_DAREA - defines the display area
-                {
-                    if ( i + 4 >= pv->buf->size )
-                    {
-                        return 1;
-                    }
-
-                    pv->x     = (buf[i+0]<<4) | ((buf[i+1]>>4)&0x0f);
-                    pv->width = (((buf[i+1]&0x0f)<<8)| buf[i+2]) - pv->x + 1;
-                    pv->y     = (buf[i+3]<<4)| ((buf[i+4]>>4)&0x0f);
-                    pv->height = (((buf[i+4]&0x0f)<<8)| buf[i+5]) - pv->y + 1;
-                    i += 6;
-                    break;
-                }
-                case 0x06: // 0x06 - SET_DSPXA - defines the pixel data addresses
-                {
-                    pv->offsets[0] = ( buf[i] << 8 ) | buf[i+1]; i += 2;
-                    pv->offsets[1] = ( buf[i] << 8 ) | buf[i+1]; i += 2;
-                    break;
-                }
-            }
-        }
-
-
-
-        if( i > next )
-        {
-            break;
-        }
-        i = next;
-    }
-    // Generate timestamps if they are not set
-    if( pv->pts_start == AV_NOPTS_VALUE )
-    {
-        // Set pts to end of last sub if the start time is unknown.
-        pv->pts_start    = pv->pts;
-        pv->scr_sequence = pv->current_scr_sequence;
-    }
-
-    return 0;
-}
-
-/***********************************************************************
- * CropSubtitle
- ***********************************************************************
- * Given a raw decoded subtitle, detects transparent borders and
- * returns a cropped subtitle in a hb_buffer_t ready to be used by
- * the renderer, or NULL if the subtitle was completely transparent
- **********************************************************************/
-static int LineIsTransparent( hb_work_object_t * w, uint8_t * p )
-{
-    hb_work_private_t * pv = w->private_data;
-    int i;
-    for( i = 0; i < pv->width; i++ )
-    {
-        if( p[i] )
-        {
-            return 0;
-        }
-    }
-    return 1;
-}
-
-static int ColumnIsTransparent( hb_work_object_t * w, uint8_t * p )
-{
-    hb_work_private_t * pv = w->private_data;
-    int i;
-    for( i = 0; i < pv->height; i++ )
-    {
-        if( p[i*pv->width] )
-        {
-            return 0;
-        }
-    }
-    return 1;
-}
-
-// Brain dead resampler.  This should really use swscale...
-// Uses Bresenham algo to pick source samples for averaging
-static void resample( uint8_t * dst, uint8_t * src, int dst_w, int src_w )
-{
-    int dst_x, src_x, err, cnt, sum, val;
-
-    if( dst_w < src_w )
-    {
-        // sample down
-        sum = 0;
-        val = 0;
-        cnt = 0;
-        err = src_w / 2;
-        dst_x = 0;
-        for( src_x = 0; src_x < src_w; src_x++ )
-        {
-            sum += src[src_x];
-            cnt++;
-            err -= dst_w;
-            if( err < 0 )
-            {
-                val = sum / cnt;
-                dst[dst_x++] = val;
-                sum = cnt = 0;
-                err += src_w;
-            }
-        }
-        for( ; dst_x < dst_w; dst_x++ )
-        {
-            dst[dst_x] = val;
-        }
-    }
-    else
-    {
-        // sample up
-        err = dst_w / 2;
-        src_x = 0;
-        for( dst_x = 0; dst_x < dst_w; dst_x++ )
-        {
-            dst[dst_x] = src[src_x];
-            err -= src_w;
-            if( err < 0 )
-            {
-                src_x++;
-                err += dst_w;
-            }
-        }
-    }
-}
-
-static hb_buffer_t * CropSubtitle( hb_work_object_t * w, uint8_t * raw )
-{
-    hb_work_private_t * pv = w->private_data;
-    int i;
-    int crop[4] = { -1,-1,-1,-1 };
-    uint8_t * alpha;
-    int realwidth, realheight;
-    hb_buffer_t * buf;
-    uint8_t * lum_in, * alpha_in, * u_in, * v_in;
-
-    alpha = raw + pv->width * pv->height;
-
-    /* Top */
-    for( i = 0; i < pv->height; i++ )
-    {
-        if( !LineIsTransparent( w, &alpha[i*pv->width] ) )
-        {
-            crop[0] = i;
-            break;
-        }
-    }
-
-    if( crop[0] < 0 )
-    {
-        /* Empty subtitle */
-        return NULL;
-    }
-
-    /* Bottom */
-    for( i = pv->height - 1; i >= 0; i-- )
-    {
-        if( !LineIsTransparent( w, &alpha[i*pv->width] ) )
-        {
-            crop[1] = i;
-            break;
-        }
-    }
-
-    /* Left */
-    for( i = 0; i < pv->width; i++ )
-    {
-        if( !ColumnIsTransparent( w, &alpha[i] ) )
-        {
-            crop[2] = i;
-            break;
-        }
-    }
-
-    /* Right */
-    for( i = pv->width - 1; i >= 0; i-- )
-    {
-        if( !ColumnIsTransparent( w, &alpha[i] ) )
-        {
-            crop[3] = i;
-            break;
-        }
-    }
-
-    realwidth  = crop[3] - crop[2] + 1;
-    realheight = crop[1] - crop[0] + 1;
-
-    buf = hb_frame_buffer_init( AV_PIX_FMT_YUVA420P, realwidth, realheight );
-    buf->s.frametype    = HB_FRAME_SUBTITLE;
-    buf->s.start        = pv->pts_start;
-    buf->s.stop         = pv->pts_stop;
-    buf->s.scr_sequence = pv->scr_sequence;
-
-    buf->f.x = pv->x + crop[2];
-    buf->f.y = pv->y + crop[0];
-    buf->f.window_width  = w->subtitle->width;
-    buf->f.window_height = w->subtitle->height;
-
-    lum_in    = raw + crop[0] * pv->width + crop[2];
-    alpha_in  = lum_in + pv->width * pv->height;
-    u_in      = alpha_in + pv->width * pv->height;
-    v_in      = u_in + pv->width * pv->height;
-
-    uint8_t *dst;
-    for( i = 0; i < realheight; i++ )
-    {
-        // Luma
-        dst = buf->plane[0].data + buf->plane[0].stride * i;
-        memcpy( dst, lum_in, realwidth );
-
-        if( ( i & 1 ) == 0 )
-        {
-            // chroma U (resample to YUV420)
-            dst = buf->plane[1].data + buf->plane[1].stride * ( i >> 1 );
-            resample( dst, u_in, buf->plane[1].width, realwidth );
-
-            // chroma V (resample to YUV420)
-            dst = buf->plane[2].data + buf->plane[2].stride * ( i >> 1 );
-            resample( dst, v_in, buf->plane[2].width, realwidth );
-        }
-        // Alpha
-        dst = buf->plane[3].data + buf->plane[3].stride * i;
-        memcpy( dst, alpha_in, realwidth );
-
-        lum_in    += pv->width;
-        alpha_in  += pv->width;
-        u_in      += pv->width;
-        v_in      += pv->width;
-    }
-
-    return buf;
-}
-
-static hb_buffer_t * Decode( hb_work_object_t * w )
-{
-    hb_work_private_t * pv = w->private_data;
-    int code, line, col;
-    int offsets[2];
-    int * offset;
-    hb_buffer_t * buf;
-    uint8_t * buf_raw = NULL;
-    hb_job_t * job = pv->job;
-
-    /* Get infos about the subtitle */
-    if ( ParseControls( w ) )
-    {
-        /*
-         * Couldn't parse the info
-         */
-        hb_deep_log( 2, "decvobsub: Could not parse info!" );
-
-        hb_buffer_close( &pv->buf );
-        return NULL;
-    }
-
-    if( job->indepth_scan || ( w->subtitle->config.force && pv->pts_forced == 0 ) )
-    {
-        /*
-         * Don't encode subtitles when doing a scan.
-         *
-         * When forcing subtitles, ignore all those that don't
-         * have the forced flag set.
-         */
-        hb_buffer_close( &pv->buf );
-        return NULL;
-    }
-
-    if (w->subtitle->config.dest == PASSTHRUSUB)
-    {
-        pv->buf->s.start        = pv->pts_start;
-        pv->buf->s.stop         = pv->pts_stop;
-        pv->buf->s.scr_sequence = pv->scr_sequence;
-        buf = pv->buf;
-        pv->buf = NULL;
-        return buf;
-    }
-
-    /* Do the actual decoding now */
-    buf_raw = malloc( ( pv->width * pv->height ) * 4 );
-
-#define GET_NEXT_NIBBLE code = ( code << 4 ) | ( ( ( *offset & 1 ) ? \
-( pv->buf->data[((*offset)>>1)] & 0xF ) : ( pv->buf->data[((*offset)>>1)] >> 4 ) ) ); \
-(*offset)++
-
-    offsets[0] = pv->offsets[0] * 2;
-    offsets[1] = pv->offsets[1] * 2;
-
-    for( line = 0; line < pv->height; line++ )
-    {
-        /* Select even or odd field */
-        offset = ( line & 1 ) ? &offsets[1] : &offsets[0];
-
-        for( col = 0; col < pv->width; col += code >> 2 )
-        {
-            uint8_t * lum, * alpha,  * chromaU, * chromaV;
-            int       idx, len;
-
-            code = 0;
-            GET_NEXT_NIBBLE;
-            if( code < 0x4 )
-            {
-                GET_NEXT_NIBBLE;
-                if( code < 0x10 )
-                {
-                    GET_NEXT_NIBBLE;
-                    if( code < 0x40 )
-                    {
-                        GET_NEXT_NIBBLE;
-                        if( code < 0x100 )
-                        {
-                            /* End of line */
-                            code |= ( pv->width - col ) << 2;
-                        }
-                    }
-                }
-            }
-
-            lum     = buf_raw;
-            alpha   = lum + pv->width * pv->height;
-            chromaU = alpha + pv->width * pv->height;
-            chromaV = chromaU + pv->width * pv->height;
-            idx     = code & 3;
-            len     = code >> 2;
-            // Protect against malformed VOBSUB with invalid run length
-            if (len > pv->width - col)
-            {
-                len = pv->width - col;
-            }
-
-            memset( lum     + line * pv->width + col, pv->lum[idx],     len );
-            memset( alpha   + line * pv->width + col, pv->alpha[idx],   len );
-            memset( chromaU + line * pv->width + col, pv->chromaU[idx], len );
-            memset( chromaV + line * pv->width + col, pv->chromaV[idx], len );
-        }
-
-        /* Byte-align */
-        if( *offset & 1 )
-        {
-            (*offset)++;
-        }
-    }
-
-    hb_buffer_close( &pv->buf );
-
-    /* Crop subtitle (remove transparent borders) */
-    buf = CropSubtitle( w, buf_raw );
-
-    free( buf_raw );
-
-    return buf;
-}
diff --git a/libhb/demuxmpeg.c b/libhb/demuxmpeg.c
index 17ade5742..2c9c25f50 100644
--- a/libhb/demuxmpeg.c
+++ b/libhb/demuxmpeg.c
@@ -222,10 +222,11 @@ static void demux_dvd_ps( hb_buffer_t * buf, hb_buffer_list_t * list_es,
             /* Here we hit we ES payload */
             buf_es = hb_buffer_init( pes_packet_end - pos );
 
-            buf_es->s.id       = id;
-            buf_es->s.start    = pts;
+            buf_es->s.id           = id;
+            buf_es->s.start        = pts;
             buf_es->s.renderOffset = dts;
-            buf_es->s.stop     = AV_NOPTS_VALUE;
+            buf_es->s.duration     = (int64_t)AV_NOPTS_VALUE;
+            buf_es->s.stop         = AV_NOPTS_VALUE;
             if ( state && id == 0xE0)
             {
                 // Consume a chapter break, and apply it to the ES.
diff --git a/libhb/dvd.c b/libhb/dvd.c
index 29ba0d54d..206c1c51e 100644
--- a/libhb/dvd.c
+++ b/libhb/dvd.c
@@ -205,7 +205,8 @@ static void add_subtitle( hb_list_t * list_subtitle, int position,
     subtitle->config.dest    = RENDERSUB;
     subtitle->stream_type    = 0xbd;
     subtitle->substream_type = 0x20 + position;
-    subtitle->codec          = WORK_DECVOBSUB;
+    subtitle->codec          = WORK_DECAVSUB;
+    subtitle->codec_param    = AV_CODEC_ID_DVD_SUBTITLE;
     subtitle->timebase.num   = 1;
     subtitle->timebase.den   = 90000;
 
diff --git a/libhb/dvdnav.c b/libhb/dvdnav.c
index 779f234ec..970ee29c5 100644
--- a/libhb/dvdnav.c
+++ b/libhb/dvdnav.c
@@ -351,7 +351,8 @@ static void add_subtitle( hb_list_t * list_subtitle, int position,
     subtitle->config.dest    = RENDERSUB;
     subtitle->stream_type    = 0xbd;
     subtitle->substream_type = 0x20 + position;
-    subtitle->codec          = WORK_DECVOBSUB;
+    subtitle->codec          = WORK_DECAVSUB;
+    subtitle->codec_param    = AV_CODEC_ID_DVD_SUBTITLE;
     subtitle->timebase.num   = 1;
     subtitle->timebase.den   = 90000;
 
diff --git a/libhb/encvobsub.c b/libhb/encvobsub.c
deleted file mode 100644
index 01315aa90..000000000
--- a/libhb/encvobsub.c
+++ /dev/null
@@ -1,75 +0,0 @@
-/* encvobsub.c
-
-   Copyright (c) 2003-2020 HandBrake Team
-   This file is part of the HandBrake source code
-   Homepage: <http://handbrake.fr/>.
-   It may be used under the terms of the GNU General Public License v2.
-   For full terms see the file COPYING file or visit http://www.gnu.org/licenses/gpl-2.0.html
- */
-
-#include "handbrake/handbrake.h"
-#include "handbrake/hbffmpeg.h"
-
-struct hb_work_private_s
-{
-    hb_job_t * job;
-};
-
-int encsubInit( hb_work_object_t * w, hb_job_t * job )
-{
-    hb_work_private_t * pv;
-
-    pv              = calloc( 1, sizeof( hb_work_private_t ) );
-    w->private_data = pv;
-
-    pv->job = job;
-
-    return 0;
-}
-
-int encsubWork( hb_work_object_t * w, hb_buffer_t ** buf_in,
-                hb_buffer_t ** buf_out )
-{
-    hb_buffer_t * in = *buf_in;
-
-    if (w->subtitle->source != VOBSUB)
-    {
-        // Invalid source, send EOF, this shouldn't ever happen
-        hb_log("encvobsub: invalid subtitle source");
-        hb_buffer_close( buf_in );
-        *buf_out = hb_buffer_eof_init();
-    }
-    if (in->s.flags & HB_BUF_FLAG_EOF)
-    {
-        /* EOF on input stream - send it downstream & say that we're done */
-        *buf_out = in;
-        *buf_in = NULL;
-        return HB_WORK_DONE;
-    }
-
-    /*
-     * Not much to do, just pass the buffer on.
-     * Some day, we may re-encode bd subtitles here ;)
-     */
-    if (buf_out)
-    {
-        *buf_out = in;
-        *buf_in = NULL;
-    }
-
-    return HB_WORK_OK;
-}
-
-void encsubClose( hb_work_object_t * w )
-{
-    free( w->private_data );
-}
-
-hb_work_object_t hb_encvobsub =
-{
-    WORK_ENCVOBSUB,
-    "VOBSUB encoder",
-    encsubInit,
-    encsubWork,
-    encsubClose
-};
diff --git a/libhb/handbrake/common.h b/libhb/handbrake/common.h
index 391e6e369..3d91be0da 100644
--- a/libhb/handbrake/common.h
+++ b/libhb/handbrake/common.h
@@ -1262,7 +1262,6 @@ extern hb_work_object_t hb_sync_video;
 extern hb_work_object_t hb_sync_audio;
 extern hb_work_object_t hb_sync_subtitle;
 extern hb_work_object_t hb_decvobsub;
-extern hb_work_object_t hb_encvobsub;
 extern hb_work_object_t hb_decsrtsub;
 extern hb_work_object_t hb_decutf8sub;
 extern hb_work_object_t hb_dectx3gsub;
diff --git a/libhb/handbrake/internal.h b/libhb/handbrake/internal.h
index 2f8fc0369..b0f1dd9fe 100644
--- a/libhb/handbrake/internal.h
+++ b/libhb/handbrake/internal.h
@@ -438,7 +438,6 @@ enum
     WORK_DECSRTSUB,
     WORK_DECTX3GSUB,
     WORK_DECSSASUB,
-    WORK_ENCVOBSUB,
     WORK_RENDER,
     WORK_ENCAVCODEC,
     WORK_ENCQSV,
diff --git a/libhb/hb.c b/libhb/hb.c
index a62052436..fcd57c3e6 100644
--- a/libhb/hb.c
+++ b/libhb/hb.c
@@ -1713,8 +1713,6 @@ int hb_global_init()
     hb_register(&hb_decsrtsub);
     hb_register(&hb_decssasub);
     hb_register(&hb_dectx3gsub);
-    hb_register(&hb_decvobsub);
-    hb_register(&hb_encvobsub);
     hb_register(&hb_encavcodec);
     hb_register(&hb_encavcodeca);
 #ifdef __APPLE__
diff --git a/libhb/rendersub.c b/libhb/rendersub.c
index a04adbe90..7f1a4badb 100644
--- a/libhb/rendersub.c
+++ b/libhb/rendersub.c
@@ -22,7 +22,7 @@ struct hb_filter_private_s
     int                 sws_width;
     int                 sws_height;
 
-    // VOBSUB
+    // VOBSUB && PGSSUB
     hb_list_t         * sub_list; // List of active subs
 
     // SSA
@@ -345,6 +345,8 @@ static void ApplyVOBSubs( hb_filter_private_t * pv, hb_buffer_t * buf )
     int ii;
     hb_buffer_t *sub, *next;
 
+    // Note that VOBSUBs can overlap in time.
+    // I.e. more than one may be rendered to the screen at once.
     for( ii = 0; ii < hb_list_count(pv->sub_list); )
     {
         sub = hb_list_item( pv->sub_list, ii );
diff --git a/libhb/stream.c b/libhb/stream.c
index bf96090bc..bb99688e0 100644
--- a/libhb/stream.c
+++ b/libhb/stream.c
@@ -1992,6 +1992,11 @@ static void pes_add_subtitle_to_title(
                     subtitle->format = PICTURESUB;
                     subtitle->config.dest = RENDERSUB;
                     break;
+                case AV_CODEC_ID_DVD_SUBTITLE:
+                    subtitle->source = VOBSUB;
+                    subtitle->format = PICTURESUB;
+                    subtitle->config.dest = RENDERSUB;
+                    break;
                 default:
                     // Unrecognized, don't add to list
                     hb_log("unrecognized subtitle!");
@@ -1999,11 +2004,6 @@ static void pes_add_subtitle_to_title(
                     return;
             }
         } break;
-        case WORK_DECVOBSUB:
-            subtitle->source = VOBSUB;
-            subtitle->format = PICTURESUB;
-            subtitle->config.dest = RENDERSUB;
-            break;
         default:
             // Unrecognized, don't add to list
             hb_log("unrecognized subtitle!");
@@ -3875,7 +3875,8 @@ static void hb_ps_stream_find_streams(hb_stream_t *stream)
                     int idx = update_ps_streams( stream, pes_info.stream_id,
                                             pes_info.bd_substream_id, 0, -1 );
                     stream->pes.list[idx].stream_kind = S;
-                    stream->pes.list[idx].codec = WORK_DECVOBSUB;
+                    stream->pes.list[idx].codec = WORK_DECAVSUB;
+                    stream->pes.list[idx].codec_param = AV_CODEC_ID_DVD_SUBTITLE;
                     strncpy(stream->pes.list[idx].codec_name,
                             "DVD Subtitle", 80);
                     continue;
@@ -4719,6 +4720,7 @@ static hb_buffer_t * generate_output_data(hb_stream_t *stream, int curstream)
             stream->ts.pcr = AV_NOPTS_VALUE;
             buf->s.start = ts_stream->pes_info.pts;
             buf->s.renderOffset = ts_stream->pes_info.dts;
+            buf->s.duration = (int64_t)AV_NOPTS_VALUE;
         }
         else
         {
@@ -5514,13 +5516,16 @@ static void add_ffmpeg_subtitle( hb_title_t *title, hb_stream_t *stream, int id
     switch ( codecpar->codec_id )
     {
         case AV_CODEC_ID_DVD_SUBTITLE:
-            subtitle->format = PICTURESUB;
-            subtitle->source = VOBSUB;
-            subtitle->config.dest = RENDERSUB;  // By default render (burn-in) the VOBSUB.
-            subtitle->codec = WORK_DECVOBSUB;
+            subtitle->format      = PICTURESUB;
+            subtitle->source      = VOBSUB;
+            subtitle->config.dest = RENDERSUB;
+            subtitle->codec       = WORK_DECAVSUB;
+            subtitle->codec_param = AV_CODEC_ID_DVD_SUBTITLE;
             if (ffmpeg_parse_vobsub_extradata(codecpar, subtitle))
+            {
                 hb_log( "add_ffmpeg_subtitle: malformed extradata for VOB subtitle track; "
                         "subtitle colors likely to be wrong" );
+            }
             break;
         case AV_CODEC_ID_DVB_SUBTITLE:
             subtitle->format      = PICTURESUB;