Introduce new codec module to decode dirac video via libschroedinger

Schroedinger is a fast decoder of the Dirac video codec.  This plugin
is currently the most complete dirac decoder (compared with ffmpeg or
codec/dirac.c) and should ideally be used in preference

- Input data blocks are handed over to schro which eventually free's them
  (avoids memcpy).  Freed by SchroBufferFree()
- Share picture storage between schro and vlc -- avoids memcpy of picture
  data after decoding.  Freed by SchroFrameFree()
- Autodetection of libschroedinger in configure.ac
  May be disabled with --disable-schroedinger
- Bumped decoding priority to 200, to beat libavcodec.c and dirac.c,
  this module does a better job than either of them.

- Remove potential memory leak when allocating pictures
- Always use p_block rather than priv in SchroBufferFree
- Performs pts interpolation for streams that do not have one pts per picture
- Set progressive, top_field_first and nb_fields on picture_t's properly
- Fix copyright date in header
- Reorder picture_pts_t structure for efficiency
- Print 64 bit types correctly with "%"PRId64
- No need to p_buffer->i_buffer=0 before buffer_Release()
- Work around schroedinger's lack of handling multiple parseunits per block
- Work around corrupt data produced by demux/ts.c after discontinuity
- Correctly reset decoder at Dirac END_OF_SEQUENCE
- Split decoding loop into two parts:
   - First, injecting [valid] parse units into the decoder
   - Second, itterating the decoder
Signed-off-by: David Flynn <davidf@woaf.net>
Signed-off-by: Rémi Denis-Courmont <rdenis@simphalempin.com>

configure.ac

@@ -3586,6 +3586,22 @@ if test "${enable_dirac}" = "yes"; then
   ])
 fi
 
+dnl
+dnl  schroedinger decoder plugin (for dirac format video)
+dnl
+AC_ARG_ENABLE(schroedinger,
+[  --disable-schroedinger   high performance dirac codec (default enabled)])
+if test "${enable_schroedinger}" != "no"; then
+  PKG_CHECK_MODULES(SCHROEDINGER,[schroedinger-1.0 >= 1.0], [
+      VLC_ADD_PLUGIN([schroedinger])
+      VLC_ADD_CFLAGS([schroedinger],[$SCHROEDINGER_CFLAGS])
+      VLC_ADD_LIBS([schroedinger],[$SCHROEDINGER_LIBS]) ], [
+        AS_IF([test "x${enable_schroedinger}" != "x"], [
+          AC_MSG_ERROR([${SCHROEDINGER_PKG_ERRORS}])
+        ])
+])
+fi
+
 dnl
 dnl  PNG decoder module
 dnl

modules/codec/Modules.am

@@ -36,3 +36,4 @@ SOURCES_cdg = cdg.c
 SOURCES_fluidsynth = fluidsynth.c
 SOURCES_cc = cc.c cc.h
 SOURCES_kate = kate.c
+SOURCES_schroedinger = schroedinger.c

modules/codec/schroedinger.c

+/*****************************************************************************
+ * schroedinger.c: Dirac decoder module making use of libschroedinger.
+ *          (http://www.bbc.co.uk/rd/projects/dirac/index.shtml)
+ *          (http://diracvideo.org)
+ *****************************************************************************
+ * Copyright (C) 2008 the VideoLAN team
+ * $Id$
+ *
+ * Authors: Jonathan Rosser <jonathan.rosser@gmail.com>
+ *          David Flynn <davidf at rd dot bbc.co.uk>
+ *
+ * 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
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Preamble
+ *****************************************************************************/
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <vlc_common.h>
+#include <vlc_plugin.h>
+#include <vlc_codec.h>
+#include <vlc_sout.h>
+#include <vlc_vout.h>
+
+#include <schroedinger/schro.h>
+
+/*****************************************************************************
+ * picture_pts_t : store pts alongside picture number, not carried through
+ * decoder
+ *****************************************************************************/
+struct picture_pts_t
+{
+   int i_empty;      //not in use
+   uint32_t u_pnum;  //picture number from dirac header
+   mtime_t i_pts;    //pts for this picture
+};
+
+/*****************************************************************************
+ * decoder_sys_t : Schroedinger decoder descriptor
+ *****************************************************************************/
+#define PTS_TLB_SIZE 16
+struct decoder_sys_t
+{
+    /*
+     * Dirac properties
+     */
+    mtime_t i_lastpts;
+    mtime_t i_frame_pts_delta;
+    SchroDecoder *p_schro;
+    SchroVideoFormat *p_format;
+    struct picture_pts_t pts_tlb[PTS_TLB_SIZE];
+    int i_ts_resync_hack;
+};
+
+/*****************************************************************************
+ * Local prototypes
+ *****************************************************************************/
+static int        OpenDecoder  ( vlc_object_t * );
+static void       CloseDecoder ( vlc_object_t * );
+static picture_t *DecodeBlock  ( decoder_t *p_dec, block_t **pp_block );
+
+/*****************************************************************************
+ * Module descriptor
+ *****************************************************************************/
+
+vlc_module_begin();
+    set_category( CAT_INPUT );
+    set_subcategory( SUBCAT_INPUT_VCODEC );
+    set_description( N_("Schroedinger video decoder") );
+    set_capability( "decoder", 200 );
+    set_callbacks( OpenDecoder, CloseDecoder );
+    add_shortcut( "schroedinger" );
+vlc_module_end();
+
+/*****************************************************************************
+ * ResetPTStlb: Purge all entries in @p_dec@'s PTS-tlb
+ *****************************************************************************/
+static void ResetPTStlb( decoder_t *p_dec )
+{
+    decoder_sys_t *p_sys = p_dec->p_sys;
+    for( int i=0; i<PTS_TLB_SIZE; i++) {
+        p_sys->pts_tlb[i].i_empty = 1;
+    }
+}
+
+/*****************************************************************************
+ * OpenDecoder: probe the decoder and return score
+ *****************************************************************************/
+static int OpenDecoder( vlc_object_t *p_this )
+{
+    decoder_t *p_dec = (decoder_t*)p_this;
+    decoder_sys_t *p_sys;
+    SchroDecoder *p_schro;
+
+    if( p_dec->fmt_in.i_codec != VLC_FOURCC('d','r','a','c') )
+    {
+        return VLC_EGENERIC;
+    }
+
+    /* Initialise the schroedinger (and hence liboil libraries */
+    /* This does no allocation and is safe to call */
+    schro_init();
+
+    /* Initialise the schroedinger decoder */
+    if( !(p_schro = schro_decoder_new()) ) return VLC_EGENERIC;
+
+    /* Allocate the memory needed to store the decoder's structure */
+    if( ( p_dec->p_sys = p_sys =
+          (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
+        return VLC_ENOMEM;
+
+    p_sys->p_schro = p_schro;
+    p_sys->p_format = NULL;
+    p_sys->i_lastpts = -1;
+    p_sys->i_frame_pts_delta = 0;
+    p_sys->i_ts_resync_hack = 0;
+
+    ResetPTStlb(p_dec);
+
+    /* Set output properties */
+    p_dec->fmt_out.i_cat = VIDEO_ES;
+    p_dec->fmt_out.i_codec = VLC_FOURCC('I','4','2','0');
+
+    /* Set callbacks */
+    p_dec->pf_decode_video = DecodeBlock;
+
+    return VLC_SUCCESS;
+}
+
+/*****************************************************************************
+ * SetPictureFormat: Set the decoded picture params to the ones from the stream
+ *****************************************************************************/
+static void SetVideoFormat( decoder_t *p_dec )
+{
+    decoder_sys_t *p_sys = p_dec->p_sys;
+    double f_aspect;
+
+    p_sys->p_format = schro_decoder_get_video_format(p_sys->p_schro);
+    if( p_sys->p_format == NULL ) return;
+
+    p_sys->i_frame_pts_delta = INT64_C(1000000)
+                            * p_sys->p_format->frame_rate_denominator
+                            / p_sys->p_format->frame_rate_numerator;
+
+    switch( p_sys->p_format->chroma_format )
+    {
+    case SCHRO_CHROMA_420: p_dec->fmt_out.i_codec = VLC_FOURCC('I','4','2','0'); break;
+    case SCHRO_CHROMA_422: p_dec->fmt_out.i_codec = VLC_FOURCC('I','4','2','2'); break;
+    case SCHRO_CHROMA_444: p_dec->fmt_out.i_codec = VLC_FOURCC('I','4','4','4'); break;
+    default:
+        p_dec->fmt_out.i_codec = 0;
+        break;
+    }
+
+    p_dec->fmt_out.video.i_visible_width =
+    p_dec->fmt_out.video.i_width = p_sys->p_format->width;
+
+    p_dec->fmt_out.video.i_visible_height =
+    p_dec->fmt_out.video.i_height = p_sys->p_format->height;
+
+    /* aspect_ratio_[numerator|denominator] describes the pixel aspect ratio */
+    f_aspect = (double)
+        ( p_sys->p_format->aspect_ratio_numerator * p_sys->p_format->width ) /
+        ( p_sys->p_format->aspect_ratio_denominator * p_sys->p_format->height);
+
+    p_dec->fmt_out.video.i_aspect = VOUT_ASPECT_FACTOR * f_aspect;
+
+    p_dec->fmt_out.video.i_frame_rate =
+        p_sys->p_format->frame_rate_numerator;
+    p_dec->fmt_out.video.i_frame_rate_base =
+        p_sys->p_format->frame_rate_denominator;
+}
+
+/*****************************************************************************
+ * StorePicturePTS: Store the PTS value for a particular picture number
+ *****************************************************************************/
+static void StorePicturePTS( decoder_t *p_dec, block_t *p_block, int i_pupos )
+{
+    decoder_sys_t *p_sys = p_dec->p_sys;
+    uint32_t u_pnum;
+    mtime_t i_pts;
+
+    u_pnum = GetDWBE( p_block->p_buffer + i_pupos + 13 );
+    i_pts = p_block->i_pts > 0 ? p_block->i_pts : p_block->i_dts;
+
+    for( int i=0; i<PTS_TLB_SIZE; i++ ) {
+        if( p_sys->pts_tlb[i].i_empty ) {
+
+            p_sys->pts_tlb[i].u_pnum = u_pnum;
+            p_sys->pts_tlb[i].i_pts = i_pts;
+            p_sys->pts_tlb[i].i_empty = 0;
+
+            return;
+        }
+    }
+
+    msg_Err( p_dec, "Could not store PTS %"PRId64" for picture %u",
+             i_pts, u_pnum );
+}
+
+/*****************************************************************************
+ * GetPicturePTS: Retrieve the PTS value for a particular picture number
+ *****************************************************************************/
+static mtime_t GetPicturePTS( decoder_t *p_dec, uint32_t u_pnum )
+{
+    decoder_sys_t *p_sys = p_dec->p_sys;
+
+    for( int i=0; i<PTS_TLB_SIZE; i++ ) {
+        if( (!p_sys->pts_tlb[i].i_empty) &&
+            (p_sys->pts_tlb[i].u_pnum == u_pnum)) {
+
+             p_sys->pts_tlb[i].i_empty = 1;
+             return p_sys->pts_tlb[i].i_pts;
+        }
+    }
+
+    msg_Err( p_dec, "Could not retrieve PTS for picture %u", u_pnum );
+    return 0;
+}
+
+/*****************************************************************************
+ * SchroFrameFree: schro_frame callback to release the associated picture_t
+ * When schro_decoder_reset() is called there will be pictures in the
+ * decoding pipeline that need to be released rather than displayed.
+ *****************************************************************************/
+static void SchroFrameFree( SchroFrame *frame, void *priv)
+{
+    picture_t *p_pic = priv;
+
+    if( !p_pic )
+        return;
+
+    if( p_pic->pf_release ) p_pic->pf_release( p_pic );
+}
+
+/*****************************************************************************
+ * CreateSchroFrameFromPic: wrap a picture_t in a SchroFrame
+ *****************************************************************************/
+static SchroFrame *CreateSchroFrameFromPic( decoder_t *p_dec )
+{
+    decoder_sys_t *p_sys = p_dec->p_sys;
+    SchroFrame *p_schroframe = schro_frame_new();
+    picture_t *p_pic = NULL;
+
+    if( !p_schroframe )
+        return NULL;
+
+    p_pic = p_dec->pf_vout_buffer_new( p_dec );
+
+    if( !p_pic )
+        return NULL;
+
+    p_schroframe->format = SCHRO_FRAME_FORMAT_U8_420;
+    if( p_sys->p_format->chroma_format == SCHRO_CHROMA_422 )
+    {
+        p_schroframe->format = SCHRO_FRAME_FORMAT_U8_422;
+    }
+    else if( p_sys->p_format->chroma_format == SCHRO_CHROMA_444 )
+    {
+        p_schroframe->format = SCHRO_FRAME_FORMAT_U8_444;
+    }
+
+    p_schroframe->width = p_sys->p_format->width;
+    p_schroframe->height = p_sys->p_format->height;
+    schro_frame_set_free_callback( p_schroframe, SchroFrameFree, p_pic );
+
+    for( int i=0; i<3; i++ )
+    {
+        p_schroframe->components[i].width = p_pic->p[i].i_visible_pitch;
+        p_schroframe->components[i].stride = p_pic->p[i].i_pitch;
+        p_schroframe->components[i].height = p_pic->p[i].i_visible_lines;
+        p_schroframe->components[i].length =
+            p_pic->p[i].i_pitch * p_pic->p[i].i_lines;
+        p_schroframe->components[i].data = p_pic->p[i].p_pixels;
+
+        if(i!=0)
+        {
+            p_schroframe->components[i].v_shift =
+                SCHRO_FRAME_FORMAT_V_SHIFT( p_schroframe->format );
+            p_schroframe->components[i].h_shift =
+                SCHRO_FRAME_FORMAT_H_SHIFT( p_schroframe->format );
+        }
+    }
+
+    p_pic->b_progressive = !p_sys->p_format->interlaced;
+    p_pic->b_top_field_first = p_sys->p_format->top_field_first;
+    p_pic->i_nb_fields = 2;
+
+    return p_schroframe;
+}
+
+/*****************************************************************************
+ * SchroBufferFree: schro_buffer callback to release the associated block_t
+ *****************************************************************************/
+static void SchroBufferFree( SchroBuffer *buf, void *priv )
+{
+    block_t *p_block = priv;
+
+    if( !p_block )
+        return;
+
+    block_Release( p_block );
+}
+
+/*****************************************************************************
+ * CloseDecoder: decoder destruction
+ *****************************************************************************/
+static void CloseDecoder( vlc_object_t *p_this )
+{
+    decoder_t *p_dec = (decoder_t *)p_this;
+    decoder_sys_t *p_sys = p_dec->p_sys;
+
+    schro_decoder_free( p_sys->p_schro );
+    free( p_sys );
+}
+
+/****************************************************************************
+ * DecodeBlock: the whole thing
+ ****************************************************************************
+ * Blocks must start with a Dirac parse unit.
+ * Blocks must contain at least one Dirac parse unit.
+ * Blocks must end with a picture parse unit.
+ * Blocks must not contain more than one picture parse unit.
+ * If a block has a PTS signaled, it applies to the first picture in p_block
+ *   - Schroedinger has no internal means to tag pictures with a PTS
+ *   - In this case, the picture number is extracted and stored in a TLB
+ * When a picture is extracted from schro, it is looked up in the pts_tlb
+ *   - If the picture was never tagged with a PTS, a new one is calculated
+ *     based upon the frame rate and last output PTS.
+ *
+ * If this function returns a picture (!NULL), it is called again and the
+ * same block is resubmitted.  To avoid this, set *pp_block to NULL;
+ * If this function returns NULL, the *pp_block is lost (and leaked).
+ * This function must free all blocks when finished with them.
+ ****************************************************************************/
+static picture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
+{
+    decoder_sys_t *p_sys = p_dec->p_sys;
+    int state;
+    SchroBuffer *p_schrobuffer;
+    SchroFrame *p_schroframe;
+    picture_t *p_pic;
+    block_t *p_block;
+    uint32_t u_pnum;
+    static int drop = 0;
+
+    if( !pp_block ) return NULL;
+
+    p_block = *pp_block;
+
+    if ( p_block ) do {
+        /* prepare block for submission */
+
+        if (p_sys->i_ts_resync_hack && p_sys->i_ts_resync_hack--)
+            return NULL;
+
+        if( !p_block->i_buffer ) {
+            msg_Err( p_dec, "block is of zero size" );
+            break;
+        }
+
+        /* reset the decoder when seeking as the decode in progress is invalid */
+        /* discard the block as it is just a null magic block */
+        if( p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) ) {
+            msg_Dbg( p_dec, "SCHRO_DECODER_RESET" );
+            schro_decoder_reset( p_sys->p_schro );
+
+            ResetPTStlb( p_dec );
+
+            p_sys->i_lastpts = -1;
+
+            /* The ts layer manages to corrupt the next packet we are to receive
+             * Since schro has no sync support, we need to drop it */
+            p_sys->i_ts_resync_hack = 1;
+
+            block_Release( p_block );
+            *pp_block = NULL;
+            return NULL;
+        }
+
+        /* Unsatisfactory, and will later be fixed in schro:
+         *  - Schro can only handle a single Dirac parse unit at a time
+         *  - Multiple parse units may exist in p_block
+         *  - All mapping specs so far guarantee that p_block would
+         *    not contain anything after a picture
+         * So, we can not give the whole block to schro, but piecemeal
+         */
+        size_t i_bufused = 0;
+        while( schro_decoder_push_ready( p_sys->p_schro )) {
+            if( p_block->i_buffer - i_bufused < 13 ) {
+                *pp_block = NULL;
+                block_Release( p_block );
+                msg_Err( p_dec, "not enough data left in block" );
+                break;
+            }
+
+            int b_bail = 0;
+            size_t i_pulen = GetDWBE( p_block->p_buffer + i_bufused + 5 );
+            uint8_t *p_pu = p_block->p_buffer + i_bufused;
+
+            /* blocks that do not start with the parse info prefix are invalid */
+            if( p_pu[0] != 'B' || p_pu[1] != 'B' ||
+                p_pu[2] != 'C' || p_pu[3] != 'D')
+            {
+                *pp_block = NULL;
+                block_Release( p_block );
+                msg_Err( p_dec, "block does not start with dirac parse code" );
+                break;
+            }
+
+            if( i_bufused + i_pulen > p_block->i_buffer ) {
+                *pp_block = NULL;
+                block_Release( p_block );
+                break;
+            }
+
+            if( p_pu[4] & 0x08 )
+                StorePicturePTS( p_dec, p_block, i_bufused );
+
+            p_schrobuffer = schro_buffer_new_with_data( p_pu, i_pulen );
+            if( i_pulen + i_bufused < p_block->i_buffer ) {
+                /* don't let schro free this block, more data still in it */
+                p_schrobuffer->free = 0;
+            }
+            else {
+                p_schrobuffer->free = SchroBufferFree;
+                p_schrobuffer->priv = p_block;
+                b_bail = 1;
+            }
+
+            msg_Dbg( p_dec, "Inserting bytes into decoder len=%d of %d pts=%"PRId64,
+                     i_pulen, p_block->i_buffer, p_block->i_pts);
+            /* this stops the same block being fed back into this function if
+             * we were on the next iteration of this loop to output a picture */
+            *pp_block = NULL;
+            state = schro_decoder_push( p_sys->p_schro, p_schrobuffer );
+
+            /* DO NOT refer to p_block after this point, it may have been freed */
+
+            i_bufused += i_pulen;
+
+            if( state == SCHRO_DECODER_FIRST_ACCESS_UNIT ) {
+                msg_Dbg( p_dec, "SCHRO_DECODER_FIRST_ACCESS_UNIT");
+                SetVideoFormat( p_dec );
+                ResetPTStlb( p_dec );
+            }
+
+            if( b_bail )
+                break;
+        }
+
+        if( (i_bufused > 0) && (i_bufused < p_block->i_buffer) )
+            msg_Err( p_dec, "not submitted everything in p_buffer");
+
+
+    } while( 0 );
+
+    while( 1 )
+    {
+        state = schro_decoder_wait( p_sys->p_schro );
+
+        switch( state )
+        {
+        case SCHRO_DECODER_NEED_BITS:
+            msg_Dbg( p_dec, "SCHRO_DECODER_NEED_BITS" );
+            return NULL;
+
+        case SCHRO_DECODER_NEED_FRAME:
+            msg_Dbg( p_dec, "SCHRO_DECODER_NEED_FRAME" );
+            p_schroframe = CreateSchroFrameFromPic( p_dec );
+
+            if( !p_schroframe )
+            {
+                msg_Err( p_dec, "Could not allocate picture for decoder");
+                return NULL;
+            }
+
+            schro_decoder_add_output_picture( p_sys->p_schro, p_schroframe);
+            break;
+
+        case SCHRO_DECODER_OK:
+            u_pnum = schro_decoder_get_picture_number( p_sys->p_schro );
+            p_schroframe = schro_decoder_pull( p_sys->p_schro );
+            p_pic = p_schroframe->priv;
+            p_schroframe->priv = NULL;
+            schro_frame_unref( p_schroframe );
+
+            /* solve presentation time stamp for picture.  If this picture
+             * was not tagged with a pts when presented to decoder, interpolate
+             * one
+             * This means no need to set p_pic->b_force, as we have a pts on
+             * each picture */
+            p_pic->date = GetPicturePTS( p_dec, u_pnum );
+            if (p_sys->i_lastpts >= 0 && p_pic->date == 0)
+                p_pic->date = p_sys->i_lastpts + p_sys->i_frame_pts_delta;
+            p_sys->i_lastpts = p_pic->date;
+
+            msg_Dbg( p_dec, "SCHRO_DECODER_OK num=%u date=%"PRId64,
+                     u_pnum, p_pic->date);
+
+            return p_pic;
+
+        case SCHRO_DECODER_EOS:
+            msg_Dbg( p_dec, "SCHRO_DECODER_EOS");
+            /* reset the decoder -- schro doesn't do this itself automatically */
+            /* there are no more pictures in the output buffer at this point */
+            schro_decoder_reset( p_sys->p_schro );
+            break;
+
+        case SCHRO_DECODER_ERROR:
+            msg_Dbg( p_dec, "SCHRO_DECODER_ERROR");
+            return NULL;
+        }
+    }
+
+    /* Never reached */
+    return NULL;
+}