[vlc-devel] [PATCH]v2 codec: Add GStreamer based decoder module

Rémi Denis-Courmont remi at remlab.net
Sat Apr 26 22:45:18 CEST 2014


Le samedi 26 avril 2014, 17:35:26 Vikram Fugro a écrit :
>  dnl
> +dnl gstreamer decode plugins
> +dnl
> +AC_ARG_ENABLE(gstreamer-decode,
> +[  --enable-gstreamer-decode        gstreamer decode plugins support,
> currently supports only video decoders (default enabled)])

I think it should default to auto, not enabled.

> +
> +dnl
> +dnl gstreamer core libs, will be mandatory for all types of gstreamer based
> modules
> +dnl
> +AS_IF([test "${enable_gstreamer_decode}" != "no"], [
> +  PKG_CHECK_MODULES(GSTREAMER_APP,[gstreamer-app-1.0], [
> +  ],[
> +    AC_MSG_ERROR([${GSTREAMER_APP_PKG_ERRORS}. Please disable all the
> gstreamer based modules to ignore this error.])
> +  ])
> +],[

Same here.

> +])
> +
> +dnl
> +dnl gstreamer plugins for decoder codec module.
> +dnl
> +AS_IF([test "${enable_gstreamer_decode}" != "no"], [
> +  dnl
> +  dnl Currently supports only video decoders
> +  dnl
> +  PKG_CHECK_MODULES(GSTREAMER_VIDEO,[gstreamer-basevideo-1.0
> gstreamer-video-1.0], [

AFAIK, gstreamer-basevideo no longer exists.

> +    VLC_SAVE_FLAGS
> +    CPPFLAGS="${CPPFLAGS} ${GSTREAMER_VIDEO_CFLAGS}
> ${GSTREAMER_APP_CFLAGS}"
> +    CFLAGS="${CFLAGS} ${GSTREAMER_VIDEO_CFLAGS}
> ${GSTREAMER_APP_CFLAGS}"

Why? you're not compiling any code here...

> +    VLC_ADD_PLUGIN([gstdecode])

No. This is redundant with the automake conditional below.

> +    VLC_ADD_LIBS([gstdecode],[$GSTREAMER_VIDEO_LIBS])
> +    VLC_ADD_LIBS([gstdecode],[$GSTREAMER_APP_LIBS])

No. This is redundant since you already have LIBADD in the Makefile.

> +    VLC_RESTORE_FLAGS
> +  ],[
> +    AC_MSG_ERROR([${GSTREAMER_VIDEO_PKG_ERRORS}. Pass
> --disable-gstreamer-decode to ignore this error.])
> +  ])

Not everybody has gstreamer. We don't want to fail by default.

> +],[
> +])
> +AM_CONDITIONAL([HAVE_GSTREAMER_DECODE], [test "${have_gstreamer_decode}" !=
> "no"])

HAVE_GSTREAMER. And I don't see where ${have_gstreamer_decode} is computed.

> +
> +dnl
>  dnl  avcodec decoder/encoder plugin
>  dnl
>  AC_ARG_ENABLE(avcodec,
> diff --git a/modules/MODULES_LIST b/modules/MODULES_LIST
> index effd694..a307635 100644
> --- a/modules/MODULES_LIST
> +++ b/modules/MODULES_LIST
> @@ -151,6 +151,7 @@ $Id$
>   * grain: Grain Video filter
>   * grey_yuv: grayscale to others conversion module
>   * growl: announce currently playing stream to growl
> + * gstdecode: GStreamer based decoder module.
>   * h264: H264 decoder
>   * headphone_channel_mixer:  headphone channel mixer with virtual
> spatialization effect * hevc: HEVC demuxer
> diff --git a/modules/codec/Makefile.am b/modules/codec/Makefile.am
> index 14500c6..dc8664f 100644
> --- a/modules/codec/Makefile.am
> +++ b/modules/codec/Makefile.am
> @@ -470,3 +470,12 @@ libquicktime_plugin_la_LDFLAGS = $(AM_LDFLAGS) -rpath
> '$(codecdir)' libquicktime_plugin_la_LIBADD = $(LIBM)
>  EXTRA_LTLIBRARIES += libquicktime_plugin.la
>  codec_LTLIBRARIES += $(LTLIBquicktime)
> +
> +libgstdecode_plugin_la_SOURCES = codec/gstdecode.c
> +libgstdecode_plugin_la_CFLAGS = $(AM_CFLAGS) $(GSTREAMER_VIDEO_CFLAGS)
> $(GSTREAMER_APP_CFLAGS)

> +libgstdecode_plugin_la_LDFLAGS = $(AM_LDFLAGS)
> -rpath '$(codecdir)'

Not needed.

> +libgstdecode_plugin_la_LIBADD =
> $(GSTREAMER_VIDEO_LIBS) $(GSTREAMER_APP_LIBS)

> +EXTRA_LTLIBRARIES += libgstdecode_plugin.la

Not needed.

> +if HAVE_GSTREAMER_DECODE
> +codec_LTLIBRARIES += $(LTLIBgstdecode)

codec_LTLIBRARIES += libgstdecode_plugin.la

> +endif
> diff --git a/modules/codec/gstdecode.c b/modules/codec/gstdecode.c
> new file mode 100644
> index 0000000..565f284
> --- /dev/null
> +++ b/modules/codec/gstdecode.c
> @@ -0,0 +1,889 @@
> +/**************************************************************************
> *** + * gstdecode.c: Decoder module making use of gstreamer
> +
> ***************************************************************************
> ** + * Copyright (C) 2014 the VideoLAN team
> + * $Id:
> + *
> + * Author: Vikram Fugro <vikram.fugro at gmail.com>
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Library General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * This library 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
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Library General Public
> + * License along with this library; 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_input.h>
> +
> +#include <assert.h>
> +#include <limits.h>
> +
> +#include <gst/gst.h>
> +#include <gst/video/video.h>
> +#include <gst/video/gstvideometa.h>
> +#include <gst/app/gstappsrc.h>
> +#include <gst/gstatomicqueue.h>
> +
> +struct decoder_sys_t
> +{
> +    GstElement* p_decoder;
> +    GstElement* p_decode_src;
> +    GstElement* p_decode_in;
> +    GstElement* p_decode_out;
> +
> +    GstBus* p_bus;
> +
> +    GstVideoInfo vinfo;
> +    GstAtomicQueue *p_que;
> +    bool b_prerolled;
> +    bool b_running;
> +
> +    bool b_out_fmt_set;
> +};
> +
> +/**************************************************************************
> *** + * Local prototypes
> +
> ***************************************************************************
> **/ +static int  OpenDecoder( vlc_object_t * );
> +static void CloseDecoder( vlc_object_t * );
> +static picture_t *DecodeBlock( decoder_t *, block_t ** );
> +
> +#define MODULE_DESCRIPTION N_( "Decoders' plugins " \
> +        "delivered by the GStreamer library. " \
> +        "Currently supports only video decoders such as " \
> +        "h264, mpeg4, wmv, mpeg2, vp8, etc. " )
> +
> +#define USEDECODEBIN_TEXT N_("Use DecodeBin")
> +#define USEDECODEBIN_LONGTEXT N_( \
> +    "DecodeBin is a container element, that can add and " \
> +    "manage multiple elements. Apart from adding the decoders, " \
> +    "decodebin also adds elementary stream parsers which can provide " \
> +    "more info such codec profile, level and other attributes, " \
> +    "in the form of GstCaps (Stream Capabilities) to decoder. " )
> +
> +vlc_module_begin ()
> +    set_shortname( "GstDecode")
> +    add_shortcut( "gstdecode" )
> +    set_category( CAT_INPUT )
> +    set_subcategory( SUBCAT_INPUT_VCODEC )
> +    /* decoder main module */
> +    set_description( N_( "GStreamer Based Decoder" ) )
> +    set_help( MODULE_DESCRIPTION )
> +    set_capability( "decoder", 50 )
> +    set_section( N_( "Decoding" ) , NULL )
> +    set_callbacks( OpenDecoder, CloseDecoder )
> +    add_bool( "use-decodebin", false, USEDECODEBIN_TEXT,
> +        USEDECODEBIN_LONGTEXT, false)
> +vlc_module_end ()
> +
> +/* gst_init() is not thread-safe, hence a thread-safe wrapper */
> +static void vlc_gst_init( void )
> +{
> +    static vlc_mutex_t init_lock = VLC_STATIC_MUTEX;
> +
> +    vlc_mutex_lock( &init_lock );
> +    gst_init( NULL, NULL );
> +    vlc_mutex_unlock( &init_lock );
> +}
> +
> +static GstStructure* vlc_to_gst_fmt( es_format_t* p_fmt )

Missing const.

> +{
> +    GstStructure* p_str = NULL;
> +
> +    switch( p_fmt->i_codec ){
> +    case VLC_CODEC_H264:
> +        p_str = gst_structure_new_empty( "video/x-h264" );
> +        gst_structure_set( p_str, "alignment", G_TYPE_STRING, "au", NULL );
> +        break;
> +    case VLC_CODEC_MP4V:
> +        p_str = gst_structure_new_empty( "video/mpeg" );
> +        gst_structure_set( p_str, "mpegversion", G_TYPE_INT, 4,
> +                "systemstream", G_TYPE_BOOLEAN, FALSE, NULL );
> +        break;
> +    case VLC_CODEC_VP8:
> +        p_str = gst_structure_new_empty( "video/x-vp8" );
> +        break;
> +    case VLC_CODEC_MPGV:
> +        p_str = gst_structure_new_empty( "video/mpeg" );
> +        gst_structure_set( p_str, "mpegversion", G_TYPE_INT, 2,
> +                "systemstream", G_TYPE_BOOLEAN, FALSE, NULL );
> +        break;
> +    case VLC_CODEC_FLV1:
> +        p_str = gst_structure_new_empty( "video/x-flash-video" );
> +        gst_structure_set( p_str, "flvversion", G_TYPE_INT, 1, NULL );
> +        break;
> +    case VLC_CODEC_WMV1:
> +        p_str = gst_structure_new_empty( "video/x-wmv" );
> +        gst_structure_set( p_str, "wmvversion", G_TYPE_INT, 1,
> +                "format", G_TYPE_STRING, "WMV1", NULL );
> +        break;
> +    case VLC_CODEC_WMV2:
> +        p_str = gst_structure_new_empty( "video/x-wmv" );
> +        gst_structure_set( p_str, "wmvversion", G_TYPE_INT, 2,
> +                "format", G_TYPE_STRING, "WMV2", NULL );
> +        break;
> +    case VLC_CODEC_WMV3:
> +        p_str = gst_structure_new_empty( "video/x-wmv" );
> +        gst_structure_set( p_str, "wmvversion", G_TYPE_INT, 3,
> +                "format", G_TYPE_STRING, "WMV3", NULL );
> +        break;
> +    case VLC_CODEC_VC1:
> +        p_str = gst_structure_new_empty( "video/x-wmv" );
> +        gst_structure_set( p_str, "wmvversion", G_TYPE_INT, 3,
> +                "format", G_TYPE_STRING, "WVC1", NULL );
> +        break;
> +    default:
> +        break;
> +    }
> +
> +    return p_str;
> +}
> +
> +/* Emitted by appsrc when serving a seek request.
> + * Seek over here is only used for flushing the buffers.
> + * Returns TRUE always, as the 'real' seek will be
> + * done by VLC framework */
> +static gboolean seek_data_cb( GstAppSrc* p_src, guint64 l_offset,
> +        gpointer p_data )
> +{
> +    decoder_t* p_dec = ( decoder_t* )p_data;
> +    msg_Dbg( p_dec, "appsrc seeking to %llu", (unsigned long long)l_offset
> );
> +    return TRUE;
> +}
> +
> +/* Emitted by decodebin when there are no more
> + * outputs. In this case it will mostly and
> + * should be one */
> +static void no_more_pads_cb( GstElement* p_ele, gpointer p_data )
> +{
> +    decoder_t* p_dec = ( decoder_t* )p_data;
> +    decoder_sys_t* p_sys = p_dec->p_sys;
> +    GstPad* p_pad;
> +
> +    msg_Dbg( p_dec, "no more pads" );
> +
> +    p_pad = gst_element_get_static_pad( p_sys->p_decode_out,
> +            "sink" );
> +    /* check if atleast one pad was linked by now */
> +    if( p_pad )
> +    {
> +        if( !gst_pad_is_linked( p_pad ) )
> +        {
> +            p_dec->b_error = true;

Dubious for thread-safety...

> +            msg_Err( p_dec, "failed to link decode out pad" );
> +        }
> +
> +        gst_object_unref( p_pad );
> +    }
> +}
> +
> +/* Emitted by decodebin and links decodebin to fakesink */
> +static void pad_added_cb( GstElement* p_ele, GstPad* p_pad, gpointer p_data
> ) +{
> +    decoder_t* p_dec = ( decoder_t* )p_data;
> +    decoder_sys_t* p_sys = p_dec->p_sys;
> +    GstPad* p_sinkpad;
> +
> +    p_sinkpad = gst_element_get_static_pad(
> +            p_sys->p_decode_out, "sink" );
> +
> +    if( p_sinkpad && !gst_pad_is_linked( p_sinkpad ) &&
> +            gst_pad_has_current_caps( p_pad ) )
> +    {
> +        GstCaps* p_caps;
> +        GstStructure* p_str;
> +
> +        p_caps = gst_pad_get_current_caps( p_pad );
> +        p_str = gst_caps_get_structure( p_caps, 0 );
> +
> +        /* We want raw caps only. More formats can also be added like
> +         * opaque data structures in case of HW decoder */
> +        if( p_str && gst_structure_has_name( p_str, "video/x-raw" ) )
> +        {
> +            if( !gst_video_info_from_caps( &p_sys->vinfo,
> +                        p_caps ) )
> +                msg_Warn( p_dec, "failed to get video info from caps" );
> +            else
> +                gst_pad_link( p_pad, p_sinkpad );
> +        }
> +
> +        gst_caps_unref( p_caps );
> +    }
> +
> +    if( p_sinkpad )
> +        gst_object_unref( p_sinkpad );
> +}
> +
> +static bool set_out_format( GstStructure* p_str,
> +        const es_format_t* p_infmt, es_format_t* p_outfmt )
> +{
> +    video_format_t *p_voutfmt, *p_vinfmt;
> +
> +    if ( !p_str || !p_infmt || !p_outfmt)
> +        return false;

Please don't handle impossible errors.

> +
> +    p_voutfmt = &p_outfmt->video;
> +    p_vinfmt = &p_infmt->video;
> +
> +    /* We are interested in raw buffers for now, but support
> +     * for opaque data formats can also be added. For eg. when
> +     * using HW  decoders for zero-copy */
> +    if( gst_structure_has_name( p_str, "video/x-raw" ) )
> +    {
> +        gboolean b_ret = FALSE;
> +
> +        p_outfmt->i_codec = vlc_fourcc_GetCodecFromString(
> +                VIDEO_ES,
> +                gst_structure_get_string ( p_str, "format" ) );
> +
> +        if( !p_outfmt->i_codec )
> +            return false;
> +
> +        b_ret = gst_structure_get_fraction( p_str,
> +                "pixel-aspect-ratio",
> +                ( gint* )&p_voutfmt->i_sar_num,
> +                ( gint* )&p_voutfmt->i_sar_den );

Either those casts are not needed, or they violate aliasing rules. Same below.

Also I am not sure why this is under "video/x-raw". Surely opaque video data 
can have an aspect ratio too. Same with the dimensions and frame rate.

> +
> +        if( !b_ret || !p_voutfmt->i_sar_num ||
> +                !p_voutfmt->i_sar_den )
> +        {
> +            p_voutfmt->i_sar_num = 1;
> +            p_voutfmt->i_sar_den = 1;
> +        }
> +
> +        b_ret = gst_structure_get_int( p_str, "width",
> +                ( gint* )&p_voutfmt->i_width ) &&
> +            gst_structure_get_int ( p_str, "height",
> +                    ( gint* )&p_voutfmt->i_height );
> +
> +        if( !b_ret || !p_voutfmt->i_width ||
> +                !p_voutfmt->i_height )
> +        {
> +            p_voutfmt->i_width = p_vinfmt->i_width;
> +            p_voutfmt->i_height = p_vinfmt->i_height;
> +        }

Is this actually possible? Shouldn't gstreamer always provide a width and 
height?

> +
> +        b_ret = gst_structure_get_fraction ( p_str, "framerate",
> +                ( gint* )&p_voutfmt->i_frame_rate,
> +                ( gint* )&p_voutfmt->i_frame_rate_base );
> +
> +        if( !b_ret || !p_voutfmt->i_frame_rate ||
> +                !p_voutfmt->i_frame_rate_base )
> +        {
> +            p_voutfmt->i_frame_rate = p_vinfmt->i_frame_rate;
> +            p_voutfmt->i_frame_rate_base = p_vinfmt->i_frame_rate_base;
> +        }
> +
> +        return true;
> +    }
> +
> +    return false;
> +}
> +
> +/* Emitted by fakesink for every buffer and sets the
> + * output format in VLC context for vout for the first
> + * buffer. Adds the buffer to the queue */
> +static void frame_handoff_cb( GstElement* p_ele, GstBuffer* p_buf,
> +        GstPad* p_pad, gpointer p_data )
> +{
> +    decoder_t* p_dec = ( decoder_t* )p_data;
> +    decoder_sys_t* p_sys = p_dec->p_sys;
> +
> +    if( unlikely( p_sys->b_out_fmt_set == false ) )

That should be !p_sys->b_out_fmt_set

But depending on the case, you can use either
i_codec == 0 or video.i_format == 0 without a new boolean. 

> +    {
> +        if( gst_pad_has_current_caps( p_pad ) )
> +        {
> +            GstCaps* p_caps;
> +            GstStructure* p_str;
> +
> +            p_caps = gst_pad_get_current_caps( p_pad );
> +
> +            if ( !gst_video_info_from_caps( &p_sys->vinfo,
> +                        p_caps ) )
> +                msg_Warn( p_dec, "failed to get video info from caps" );

Is this really a recoverable error?

> +
> +            p_str = gst_caps_get_structure( p_caps, 0 );
> +            p_sys->b_out_fmt_set = set_out_format( p_str, &p_dec->fmt_in,
> +                    &p_dec->fmt_out );
> +
> +            gst_caps_unref( p_caps );
> +        }
> +
> +        if( !p_sys->b_out_fmt_set )
> +            return;
> +    }
> +
> +    /* Push the buffer to the queue */
> +    gst_atomic_queue_push( p_sys->p_que, gst_buffer_ref( p_buf ) );
> +}
> +
> +/* Copy the frame data from the GstBuffer (from decoder)
> + * to the picture obtained from downstream in VLC.
> + * TODO(Zero-Copy): This function should be avoided as much
> + * as possible, since it involves a a complete frame copy. */
> +static void gst_CopyPicture( picture_t *p_pic, GstVideoFrame *frame )
> +{
> +    int i_plane, i_planes, i_line, i_dst_stride, i_src_stride;
> +    uint8_t *p_dst, *p_src;
> +    int i_w, i_h;
> +
> +    i_planes = p_pic->i_planes < 3 ? p_pic->i_planes : 3;

Why is this capped to 3? If the gstreamer output format is unsupported, we 
should hopefully not reach this code at all.

> +    for( i_plane = 0; i_plane < i_planes; i_plane++ )
> +    {
> +        p_dst = p_pic->p[i_plane].p_pixels;
> +        p_src = GST_VIDEO_FRAME_PLANE_DATA( frame, i_plane );
> +        i_dst_stride  = p_pic->p[i_plane].i_pitch;
> +        i_src_stride  = GST_VIDEO_FRAME_PLANE_STRIDE( frame, i_plane );
> +
> +        i_w = GST_VIDEO_FRAME_COMP_WIDTH( frame,
> +                i_plane ) * GST_VIDEO_FRAME_COMP_PSTRIDE( frame, i_plane );
> +        i_h = GST_VIDEO_FRAME_COMP_HEIGHT( frame, i_plane );
> +
> +        for( i_line = 0;
> +                i_line < __MIN( p_pic->p[i_plane].i_lines, i_h );
> +                i_line++ )
> +        {
> +            memcpy( p_dst, p_src, i_w );
> +            p_src += i_src_stride;
> +            p_dst += i_dst_stride;
> +        }
> +    }
> +}
> +
> +/* Check if the element can use this caps */
> +static gint find_decoder_func( gconstpointer p_p1, gconstpointer p_p2 )
> +{
> +    GstElementFactory *p_factory;
> +    GstCaps* p_caps;
> +
> +    p_factory = ( GstElementFactory* )p_p1;
> +    p_caps = ( GstCaps * )p_p2;
> +
> +    return( !gst_element_factory_can_sink_any_caps( p_factory, p_caps ) );
> +}
> +
> +/**************************************************************************
> *** + * 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;
> +    GstStateChangeReturn i_ret;
> +    gboolean b_ret;
> +    GstCaps* p_caps = NULL;
> +    GstStructure* p_str = NULL;
> +    GstAppSrcCallbacks cb;
> +    int i_rval = VLC_SUCCESS;
> +    GList* p_list = NULL;
> +    bool dbin;
> +
> +#define VLC_GST_CHECK(r, v, s, t) \
> +    { if(r == v) { msg_Err(p_dec, s); i_rval = t; goto fail; } }
> +
> +    vlc_gst_init ( );
> +
> +    p_str = vlc_to_gst_fmt( &p_dec->fmt_in );
> +    if( !p_str ) {
> +        return VLC_EGENERIC;
> +    }
> +
> +    /* Allocate the memory needed to store the decoder's structure */
> +    if( ( p_dec->p_sys = p_sys = calloc( 1, sizeof( *p_sys ) ) ) == NULL )
> +        return VLC_ENOMEM;

Leaking p_str.

> +
> +    dbin = var_CreateGetBool( p_dec, "use-decodebin" );
> +    msg_Info( p_dec, "Using decodebin? %s", dbin ? "yes ":"no" );
> +
> +    /* Force packetized for now */
> +    p_dec->b_need_packetized = true;
> +

> +    if( p_dec->fmt_in.video.i_width &&
> +            p_dec->fmt_in.video.i_height )
> +    {
> +        gst_structure_set( p_str,
> +                "width", G_TYPE_INT, p_dec->fmt_in.video.i_width,
> +                "height", G_TYPE_INT, p_dec->fmt_in.video.i_height, NULL );
> +    }
> +
> +    if( p_dec->fmt_in.video.i_frame_rate &&
> +            p_dec->fmt_in.video.i_frame_rate_base )
> +    {
> +        gst_structure_set( p_str, "framerate", GST_TYPE_FRACTION,
> +                p_dec->fmt_in.video.i_frame_rate,
> +                p_dec->fmt_in.video.i_frame_rate_base, NULL );
> +    }
> +
> +    if( p_dec->fmt_in.video.i_sar_num &&
> +            p_dec->fmt_in.video.i_sar_den )
> +    {
> +        gst_structure_set( p_str, "pixel-aspect-ratio", GST_TYPE_FRACTION,
> +                p_dec->fmt_in.video.i_sar_num,
> +                p_dec->fmt_in.video.i_sar_den, NULL );
> +    }
> +
> +    if( p_dec->fmt_in.i_extra )
> +    {
> +        GstBuffer* p_buf;
> +
> +        p_buf = gst_buffer_new_wrapped_full( GST_MEMORY_FLAG_READONLY,
> +                p_dec->fmt_in.p_extra, p_dec->fmt_in.i_extra, 0,
> +                p_dec->fmt_in.i_extra, NULL, NULL );
> +        VLC_GST_CHECK( p_buf, NULL, "failed to create codec data
> gstbuffer", +                VLC_ENOMEM );
> +
> +        gst_structure_set( p_str, "codec_data", GST_TYPE_BUFFER, p_buf,
> NULL );
> +        gst_buffer_unref( p_buf );
> +    }

Why is that block not part of vlc_to_gst_fmt() ?

> +
> +    p_caps = gst_caps_new_empty( );
> +    gst_caps_append_structure( p_caps, p_str );
> +    p_str = NULL;
> +
> +    /* Get the list of all the available gstreamer decoders */
> +    p_list = gst_element_factory_list_get_elements(
> +            GST_ELEMENT_FACTORY_TYPE_DECODER, GST_RANK_MARGINAL );
> +    VLC_GST_CHECK( p_list, NULL, "no decoder list found", VLC_ENOMOD );
> +    if( !dbin )
> +    {
> +        GList* p_l;
> +        /* Sort them as per ranks */
> +        p_list = g_list_sort( p_list, gst_plugin_feature_rank_compare_func
> ); +        VLC_GST_CHECK( p_list, NULL, "failed to sort decoders list", + 
>               VLC_ENOMOD );
> +        p_l = g_list_find_custom( p_list, p_caps, find_decoder_func );
> +        VLC_GST_CHECK( p_l, NULL, "no suitable decoder found",
> +                VLC_ENOMOD );
> +        /* create the decoder with highest rank */
> +        p_sys->p_decode_in = gst_element_factory_create(
> +                (GstElementFactory*)p_l->data, NULL );
> +        VLC_GST_CHECK( p_sys->p_decode_in, NULL,
> +                "failed to create decoder", VLC_ENOMOD );
> +    }
> +    else
> +    {
> +        GList* p_l;
> +        /* Just check if any suitable decoder exists, rest will be
> +         * handled by decodebin */
> +        p_l = g_list_find_custom( p_list, p_caps, find_decoder_func );
> +        VLC_GST_CHECK( p_l, NULL, "no suitable decoder found",
> +                VLC_ENOMOD );
> +    }
> +    gst_plugin_feature_list_free( p_list );
> +    p_list = NULL;
> +
> +    p_dec->fmt_out.i_cat = VIDEO_ES;
> +
> +    p_sys->b_prerolled = false;
> +    p_sys->b_running = false;
> +    p_sys->b_out_fmt_set = false;
> +
> +    /* Queue: GStreamer thread will dump buffers into this queue,
> +     * DecodeBlock() will pop out the buffers from the queue */
> +    p_sys->p_que = gst_atomic_queue_new( 0 );
> +    VLC_GST_CHECK ( p_sys->p_que, NULL, "failed to create queue",
> +            VLC_ENOMEM );
> +
> +    p_sys->p_decode_src = gst_element_factory_make( "appsrc", NULL );
> +    VLC_GST_CHECK( p_sys->p_decode_src, NULL, "appsrc not found",
> +            VLC_ENOMOD );
> +    g_object_set( G_OBJECT( p_sys->p_decode_src ), "caps", p_caps,
> +            "block", FALSE, "emit-signals", TRUE, "format",
> GST_FORMAT_BYTES, +            "stream-type", GST_APP_STREAM_TYPE_SEEKABLE,
> +            /* Making the appsrc to block. This will make the push_buffer()
> +             * tightly coupled with the buffer flow from appsrc ->
> decoder. +             * push_buffer() will only return when the buffer has
> been fed +             * to the decoder element */
> +            "block", TRUE, "max-bytes", ( guint64 )1, NULL );
> +    gst_caps_unref( p_caps );
> +    p_caps = NULL;
> +    cb.enough_data = cb.need_data = NULL;
> +    cb.seek_data = seek_data_cb;
> +    gst_app_src_set_callbacks( GST_APP_SRC( p_sys->p_decode_src ),
> +            &cb, p_dec, NULL );
> +
> +    if( dbin )
> +    {
> +        p_sys->p_decode_in = gst_element_factory_make( "decodebin", NULL );
> +        VLC_GST_CHECK( p_sys->p_decode_in, NULL, "decodebin not found", + 
>               VLC_ENOMOD );
> +        //g_object_set( G_OBJECT (p_sys->p_decode_in),
> +        //"max-size-buffers", 2, NULL );
> +        g_signal_connect( G_OBJECT( p_sys->p_decode_in ), "pad-added",
> +                G_CALLBACK( pad_added_cb ), p_dec );
> +        g_signal_connect (G_OBJECT( p_sys->p_decode_in ), "no-more-pads",
> +                G_CALLBACK( no_more_pads_cb ), p_dec );
> +    }
> +
> +    /* fakesink: will emit signal for every available buffer */
> +    p_sys->p_decode_out = gst_element_factory_make( "fakesink", NULL );
> +    VLC_GST_CHECK( p_sys->p_decode_out, NULL, "fakesink not found",
> +            VLC_ENOMOD );
> +    /* connect to the signal with the callback */
> +    g_object_set( G_OBJECT( p_sys->p_decode_out ), "sync", FALSE,
> +            "enable-last-sample", FALSE, "signal-handoffs", TRUE, NULL );
> +    g_signal_connect( G_OBJECT( p_sys->p_decode_out ), "handoff",
> +            G_CALLBACK( frame_handoff_cb ), p_dec );
> +
> +    p_sys->p_decoder = GST_ELEMENT( gst_bin_new( "decoder" ) );
> +    VLC_GST_CHECK( p_sys->p_decoder, NULL, "bin not found", VLC_ENOMOD );
> +    p_sys->p_bus = gst_bus_new( );
> +    VLC_GST_CHECK( p_sys->p_bus, NULL, "failed to create bus",
> +            VLC_ENOMOD );
> +    gst_element_set_bus( p_sys->p_decoder, p_sys->p_bus );
> +
> +    gst_bin_add_many( GST_BIN( p_sys->p_decoder ),
> +            p_sys->p_decode_src, p_sys->p_decode_in,
> +            p_sys->p_decode_out, NULL );
> +    gst_object_ref( p_sys->p_decode_src );
> +    gst_object_ref( p_sys->p_decode_in );
> +    gst_object_ref( p_sys->p_decode_out );
> +
> +    b_ret = gst_element_link( p_sys->p_decode_src, p_sys->p_decode_in );
> +    VLC_GST_CHECK ( b_ret, FALSE, "failed to link src <-> in",
> +            VLC_EGENERIC );
> +
> +    if( !dbin )
> +    {
> +        b_ret = gst_element_link( p_sys->p_decode_in, p_sys->p_decode_out
> ); +        VLC_GST_CHECK (b_ret, FALSE, "failed to link in <-> out", +    
>            VLC_EGENERIC );
> +    }
> +
> +    /* set the pipeline to playing */
> +    i_ret = gst_element_set_state( p_sys->p_decoder, GST_STATE_PLAYING );
> +    VLC_GST_CHECK( i_ret, GST_STATE_CHANGE_FAILURE,
> +            "set state failure", VLC_EGENERIC );
> +
> +    p_sys->b_running = true;
> +
> +    /* Set callbacks */
> +    p_dec->pf_decode_video = DecodeBlock;
> +
> +    return VLC_SUCCESS;
> +
> +fail:
> +    if( p_caps )
> +    {
> +        gst_caps_unref( p_caps );
> +        p_str = NULL;
> +    }
> +    if( p_str )
> +        gst_structure_free( p_str );
> +    if( p_list )
> +        gst_plugin_feature_list_free( p_list );
> +    CloseDecoder( ( vlc_object_t* )p_dec );
> +    return i_rval;
> +}
> +
> +/* Decode */
> +static picture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
> +{
> +    block_t *p_block;
> +    picture_t *p_pic = NULL;
> +    decoder_sys_t *p_sys = p_dec->p_sys;
> +    GstMessage* p_msg;
> +    gboolean b_ret;
> +    GstBuffer* p_buf;
> +
> +    if( !pp_block )
> +        return NULL;
> +
> +    p_block = *pp_block;
> +
> +    if( p_block )
> +    {
> +        if( unlikely( p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY |
> +                        BLOCK_FLAG_CORRUPTED ) ) )
> +        {
> +            if ( p_block->i_flags & BLOCK_FLAG_DISCONTINUITY )
> +            {
> +                GstBuffer* p_buffer;
> +                /* Send a new segment event. Seeking position is
> +                 * irrelavant in this case, as the main motive for a
> +                 * seek here, is to tell the elements to start flushing
> +                 * and start accepting buffers from a new time segment */
> +                b_ret = gst_element_seek_simple( p_sys->p_decoder,
> +                        GST_FORMAT_BYTES, GST_SEEK_FLAG_FLUSH, 0 );
> +                msg_Dbg( p_dec, "new segment event : %d", b_ret );
> +
> +                /* flush the output buffers from the queue */
> +                while( ( p_buffer = gst_atomic_queue_pop( p_sys->p_que ) )
> ) +                    gst_buffer_unref ( p_buffer );
> +
> +                p_sys->b_prerolled = false;
> +            }
> +
> +            block_Release( p_block );
> +            goto done;
> +        }
> +
> +        if( likely( p_block->i_buffer ) )
> +        {
> +            p_buf = gst_buffer_new_wrapped_full( GST_MEMORY_FLAG_READONLY,
> +                    p_block->p_start, p_block->i_size,
> +                    p_block->p_buffer - p_block->p_start,
> p_block->i_buffer,
> +                    p_block, ( GDestroyNotify )block_Release );

Is that a valid function pointer cast?

> +            if( unlikely( p_buf == NULL ) )
> +            {
> +                msg_Err( p_dec, "failed to create input gstbuffer" );
> +                p_dec->b_error = true;
> +                block_Release( p_block );
> +                goto done;
> +            }
> +
> +            if( p_block->i_dts > VLC_TS_INVALID )
> +                GST_BUFFER_DTS( p_buf ) = gst_util_uint64_scale(
> p_block->i_dts, +                        GST_SECOND, GST_MSECOND );
> +
> +            if( p_block->i_pts <= VLC_TS_INVALID )
> +                GST_BUFFER_PTS( p_buf ) = GST_BUFFER_DTS( p_buf );
> +            else
> +                GST_BUFFER_PTS( p_buf ) = gst_util_uint64_scale(
> p_block->i_pts, +                        GST_SECOND, GST_MSECOND );
> +
> +            if( p_block->i_length > VLC_TS_INVALID )
> +                GST_BUFFER_DURATION( p_buf ) = gst_util_uint64_scale(
> +                        p_block->i_length, GST_SECOND, GST_MSECOND );
> +
> +            if( p_dec->fmt_in.video.i_frame_rate  &&
> +                    p_dec->fmt_in.video.i_frame_rate_base )
> +                GST_BUFFER_DURATION( p_buf ) = gst_util_uint64_scale(
> GST_SECOND, +                        p_dec->fmt_in.video.i_frame_rate_base,
> +                        p_dec->fmt_in.video.i_frame_rate );
> +
> +            /* Give the input buffer to GStreamer Bin.
> +             *
> +             *  libvlc                     libvlc
> +             *    \ (i/p)              (o/p) ^
> +             *     \                        /
> +             *   ___v____GSTREAMER BIN_____/____
> +             *  |                               |
> +             *  |   appsrc-->decode-->fakesink  |
> +             *  |_______________________________|
> +             *
> +             * * * * * * * * * * * * * * * * * * * * */
> +            if( unlikely( gst_app_src_push_buffer(
> +                            GST_APP_SRC_CAST( p_sys->p_decode_src ), p_buf
> ) +                        != GST_FLOW_OK ) )
> +            {
> +                p_dec->b_error = true;
> +                msg_Err( p_dec, "failed to push buffer" );
> +                goto done;
> +            }
> +        }
> +        else
> +            block_Release( p_block );
> +    }
> +

> +    /* Poll for any messages, errors */
> +    p_msg = gst_bus_pop_filtered( p_sys->p_bus,
> +            GST_MESSAGE_ASYNC_DONE | GST_MESSAGE_ERROR |
> +            GST_MESSAGE_EOS | GST_MESSAGE_WARNING |
> +            GST_MESSAGE_INFO );
> +    if( p_msg )
> +    {
> +        switch( GST_MESSAGE_TYPE( p_msg ) ){
> +        case GST_MESSAGE_ERROR:
> +            {
> +                gchar  *psz_debug;
> +                GError *p_error;
> +
> +                gst_message_parse_error (p_msg, &p_error, &psz_debug);
> +                g_free (psz_debug);
> +
> +                msg_Err( p_dec, "Error from %s: %s",
> +                        GST_ELEMENT_NAME( GST_MESSAGE_SRC( p_msg ) ),
> +                        p_error->message );
> +                g_error_free( p_error );
> +                p_dec->b_error = true;
> +
> +            }
> +            goto done;
> +        case GST_MESSAGE_EOS:
> +            /* for debugging purpose */
> +            msg_Warn( p_dec, "got unexpected eos" );
> +            break;
> +        /* First buffer received */
> +        case GST_MESSAGE_ASYNC_DONE:
> +            /* for debugging purpose */
> +            p_sys->b_prerolled = true;
> +            msg_Dbg( p_dec, "Pipeline is prerolled" );
> +            break;
> +        case GST_MESSAGE_INFO:
> +            {
> +                gchar  *psz_debug;
> +                GError *p_error;
> +
> +                gst_message_parse_info( p_msg, &p_error, &psz_debug );
> +                g_free( psz_debug );
> +
> +                msg_Info( p_dec, "Info from %s: %s",
> +                        GST_ELEMENT_NAME( GST_MESSAGE_SRC( p_msg ) ),
> +                        p_error->message );
> +                g_error_free( p_error );
> +            }
> +            break;
> +        case GST_MESSAGE_WARNING:
> +            {
> +                gchar  *psz_debug;
> +                GError *p_error;
> +
> +                gst_message_parse_info( p_msg, &p_error, &psz_debug );
> +                g_free( psz_debug );
> +
> +                msg_Warn( p_dec, "Warning from %s: %s",
> +                        GST_ELEMENT_NAME( GST_MESSAGE_SRC( p_msg ) ),
> +                        p_error->message );
> +                g_error_free( p_error );
> +            }
> +            break;
> +        default:
> +            break;
> +        }
> +        gst_message_unref( p_msg );
> +    }

This block seems like it could be split to a separate function and reused in 
CloseDecoder().

> +
> +    /* Look for any output buffers in the queue */
> +    if( gst_atomic_queue_peek( p_sys->p_que ) ) {
> +        /* Get a new picture */
> +        p_pic = decoder_NewPicture( p_dec );
> +
> +        if( p_pic )
> +        {
> +            p_buf = GST_BUFFER_CAST(
> +                    gst_atomic_queue_pop( p_sys->p_que ) );
> +            GstVideoFrame frame;
> +
> +            if( likely( GST_BUFFER_PTS_IS_VALID( p_buf ) ) )
> +            {
> +                p_pic->date = gst_util_uint64_scale(
> +                        GST_BUFFER_PTS( p_buf ), GST_MSECOND, GST_SECOND );
> +            }
> +
> +            if( unlikely( !gst_video_frame_map( &frame,
> +                            &p_sys->vinfo, p_buf, GST_MAP_READ ) ) )
> +            {
> +                msg_Err( p_dec, "failed to map gst video frame" );
> +                gst_buffer_unref( p_buf );
> +                p_dec->b_error = true;
> +                goto done;
> +            }
> +            else
> +            {
> +                gst_CopyPicture( p_pic, &frame );
> +                gst_video_frame_unmap( &frame );
> +            }
> +
> +            gst_buffer_unref( p_buf );
> +        }
> +    }
> +
> +done:
> +    *pp_block = NULL;
> +    return p_pic;
> +}
> +
> +/* Close the decoder instance */
> +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;
> +
> +    if( p_sys == NULL )
> +        return;

That should be impossible.

> +
> +    if( p_sys->b_running )
> +    {
> +        GstMessage* p_msg;
> +        GstFlowReturn i_ret;
> +
> +        /* Send EOS to the pipeline */
> +        i_ret = gst_app_src_end_of_stream(
> +                GST_APP_SRC_CAST( p_sys->p_decode_src ) );
> +        msg_Dbg( p_dec, "app src eos: %s", gst_flow_get_name( i_ret ) );
> +
> +        /* and catch it on the bus with a timeout */
> +        p_msg = gst_bus_timed_pop_filtered( p_sys->p_bus,
> +                2000000000ULL, GST_MESSAGE_EOS | GST_MESSAGE_ERROR );
> +
> +        if( p_msg )
> +        {
> +            switch( GST_MESSAGE_TYPE( p_msg ) ){
> +            case GST_MESSAGE_ERROR:
> +                {
> +                    gchar  *psz_debug;
> +                    GError *p_error;
> +
> +                    gst_message_parse_error ( p_msg, &p_error, &psz_debug
> ); +                    g_free( psz_debug );
> +
> +                    msg_Err( p_dec, "Error when shutting down, from %s:
> %s", +                            GST_ELEMENT_NAME( GST_MESSAGE_SRC( p_msg
> ) ), +                            p_error->message );
> +                    g_error_free( p_error );
> +                }
> +                break;
> +            case GST_MESSAGE_EOS:
> +                msg_Dbg( p_dec, "got eos" );
> +                break;
> +            default:
> +                break;
> +            }
> +
> +            gst_message_unref( p_msg );
> +        }
> +        else
> +        {
> +            msg_Warn( p_dec,
> +                    "no message, pipeline may not close gracefully" );
> +        }
> +    }
> +
> +    /* Remove any left-over buffers from the queue */
> +    if( p_sys->p_que )
> +    {
> +        GstBuffer* p_buf;
> +        while( ( p_buf = gst_atomic_queue_pop( p_sys->p_que ) ) )
> +            gst_buffer_unref( p_buf );
> +        gst_atomic_queue_unref( p_sys->p_que );
> +    }
> +
> +    if( p_sys->b_running &&
> +            gst_element_set_state( p_sys->p_decoder, GST_STATE_NULL )
> +            != GST_STATE_CHANGE_SUCCESS )
> +        msg_Warn( p_dec,
> +                "failed to change the state to NULL" \
> +                "pipeline may not close gracefully" );
> +
> +    if( p_sys->p_bus )
> +        gst_object_unref( p_sys->p_bus );
> +    if( p_sys->p_decode_src )
> +        gst_object_unref( p_sys->p_decode_src );
> +    if( p_sys->p_decode_in )
> +        gst_object_unref( p_sys->p_decode_in );
> +    if( p_sys->p_decode_out )
> +        gst_object_unref( p_sys->p_decode_out );
> +    if( p_sys->p_decoder )
> +        gst_object_unref( p_sys->p_decoder);
> +
> +    free( p_sys );
> +}
> diff --git a/po/POTFILES.in b/po/POTFILES.in
> index 0a86072..49c997d 100644
> --- a/po/POTFILES.in
> +++ b/po/POTFILES.in
> @@ -372,6 +372,7 @@ modules/codec/fdkaac.c
>  modules/codec/flac.c
>  modules/codec/fluidsynth.c
>  modules/codec/g711.c
> +modules/codec/gstdecode.c
>  modules/codec/jpeg.c
>  modules/codec/kate.c
>  modules/codec/libass.c

-- 
Rémi Denis-Courmont
http://www.remlab.net/





More information about the vlc-devel mailing list