mime multipart jpeg and jpeg series of images demuxer by

Henry Jen (slowhog) <henryjen at ztune dot net>. Only tested in multipart
mode.

modules/demux/Modules.am

@@ -21,3 +21,4 @@ SOURCES_mod = mod.c
 SOURCES_pva = pva.c
 SOURCES_aiff = aiff.c
 SOURCES_sgimb = sgimb.c
+SOURCES_mjpeg = mjpeg.c

modules/demux/mjpeg.c

+/*****************************************************************************
+ * mjpeg.c : demuxes mjpeg webcam http streams
+ *****************************************************************************
+ * Copyright (C) 2004 VideoLAN
+ * $Id: mjpeg.c 7196 2004-03-29 21:29:31Z fenrir $
+ *
+ * Authors: Henry Jen (slowhog) <henryjen@ztune.net>
+ *          Derk-Jan Hartman (thedj)
+ *          Sigmund Augdal (Dnumgis)
+ *          Laurent Aimar <fenrir@via.ecp.fr>
+ *
+ * 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., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Preamble
+ *****************************************************************************/
+#include <stdlib.h>                                      /* malloc(), free() */
+
+#include <vlc/vlc.h>
+#include <vlc/input.h>
+
+#include <codecs.h>
+
+/*****************************************************************************
+ * Module descriptor
+ *****************************************************************************/
+static int  Open ( vlc_object_t * );
+static void Close( vlc_object_t * );
+
+#define FPS_TEXT N_("Frames per Second")
+#define FPS_LONGTEXT N_("Allows you to set the desired frame rate when " \
+    "playing from files, use 0 for live.")
+#define VAR_FPS "mjpeg-fps"
+
+vlc_module_begin();
+    set_description( _("JPEG camera demuxer") );
+    set_capability( "demux2", 5 );
+    set_callbacks( Open, Close );
+    add_float( VAR_FPS, 0.0, NULL, FPS_TEXT, FPS_LONGTEXT, VLC_FALSE );
+vlc_module_end();
+
+/*****************************************************************************
+ * Local prototypes
+ *****************************************************************************/
+static int MimeDemux( demux_t * );
+static int MjpgDemux( demux_t * );
+static int Control( demux_t *, int i_query, va_list args );
+
+struct demux_sys_t
+{
+    es_format_t     fmt;
+    es_out_id_t     *p_es;
+
+    int64_t         i_data_pos;
+    unsigned int    i_data_size;
+
+    mtime_t         i_time;
+    mtime_t         i_frame_length;
+    char            *psz_separator;
+    int             i_frame_size_estimate;
+    uint8_t         *p_peek;
+    int             i_data_peeked;
+};
+
+/*****************************************************************************
+ * Peek: Helper function to peek data with incremental size. 
+ * \return VLC_FALSE if peek no more data, VLC_TRUE otherwise.
+ *****************************************************************************/
+static vlc_bool_t Peek( demux_t *p_demux, vlc_bool_t b_first )
+{
+    int i_data;
+    demux_sys_t *p_sys = p_demux->p_sys;
+
+    if( b_first )
+    {
+        p_sys->i_data_peeked = 0;
+    }
+    else if( p_sys->i_data_peeked == p_sys->i_frame_size_estimate )
+    {
+        p_sys->i_frame_size_estimate += 5120;
+    }
+    i_data = stream_Peek( p_demux->s, &p_sys->p_peek, p_sys->i_frame_size_estimate );
+    if( i_data == p_sys->i_data_peeked )
+    {
+        msg_Warn( p_demux, "no more data" );
+        return VLC_FALSE;
+    }
+    p_sys->i_data_peeked = i_data;
+    if( i_data <= 0 )
+    {
+        msg_Warn( p_demux, "cannot peek data" );
+        return VLC_FALSE;
+    }
+    return VLC_TRUE;
+}
+
+/*****************************************************************************
+ * GetLine: Internal function used to dup a line of string from the buffer
+ *****************************************************************************/
+static char* GetLine( demux_t *p_demux, int *p_pos )
+{
+    demux_sys_t *p_sys = p_demux->p_sys;
+    uint8_t     *p_buf;
+    int         i_size;
+    int         i;
+    char        *p_line;
+
+    while( *p_pos > p_sys->i_data_peeked )
+    {
+        if( ! Peek( p_demux, VLC_FALSE ) )
+        {
+            return NULL;
+        }
+    }
+    p_buf = p_sys->p_peek + *p_pos;
+    i_size = p_sys->i_data_peeked - *p_pos;
+    i = 0;
+    while( p_buf[i] != '\n' )
+    {
+        i++;
+        if( i == i_size )
+        {
+            if( ! Peek( p_demux, VLC_FALSE ) )
+            {
+                return NULL;
+            }
+        }
+        p_buf = p_sys->p_peek + *p_pos;
+        i_size = p_sys->i_data_peeked - *p_pos;
+    }
+    *p_pos += ( i + 1 );
+    if( i > 0 && '\r' == p_buf[i - 1] )
+    {
+        i--;
+    }
+    p_line = malloc( i + 1 );
+    if( NULL == p_line )
+    {
+        msg_Err( p_demux, "out of memory" );
+        return NULL;
+    }
+    strncpy ( p_line, p_buf, i );
+    p_line[i] = '\0';
+//    msg_Dbg( p_demux, "i = %d, pos = %d, %s", i, *p_pos, p_line );
+    return p_line;
+}
+
+/*****************************************************************************
+ * CheckMimeHeader: Internal function used to verify and skip mime header
+ * \param p_header_size Return size of MIME header, 0 if no MIME header
+ * detected, minus value if error
+ * \return VLC_TRUE if content type is image/jpeg, VLC_FALSE otherwise
+ *****************************************************************************/
+static vlc_bool_t CheckMimeHeader( demux_t *p_demux, int *p_header_size )
+{
+    vlc_bool_t  b_jpeg = VLC_FALSE;
+    int         i_pos;
+    char        *psz_line;
+    char	*p_ch;
+    demux_sys_t *p_sys = p_demux->p_sys;
+
+    if( !Peek( p_demux, VLC_TRUE ) )
+    {
+        msg_Err( p_demux, "cannot peek" );
+        *p_header_size = -1;
+        return VLC_FALSE;
+    }
+    if( p_sys->i_data_peeked < 3)
+    {
+        msg_Err( p_demux, "data shortage" );
+        *p_header_size = -2;
+        return VLC_FALSE;
+    }
+    if( strncmp( p_sys->p_peek, "--", 2 ) )
+    {
+        *p_header_size = 0;
+        return VLC_FALSE;
+    }
+    i_pos = 2;
+    psz_line = GetLine( p_demux, &i_pos );
+    if( NULL == psz_line )
+    {
+        msg_Err( p_demux, "no EOL" );
+        *p_header_size = -3;
+        return VLC_FALSE;
+    }
+    if( NULL == p_sys->psz_separator )
+    {
+        p_sys->psz_separator = psz_line;
+        msg_Dbg( p_demux, "Multipart MIME detected, using separator: %s", p_sys->psz_separator );
+    }
+    else
+    {
+        if( strcmp( psz_line, p_sys->psz_separator ) )
+        {
+            msg_Warn( p_demux, "separator %s does not match %s", psz_line, p_sys->psz_separator );
+        }
+        free( psz_line );
+    }
+    psz_line = GetLine( p_demux, &i_pos );
+    while( psz_line && *psz_line )
+    {
+        msg_Dbg( p_demux, "%s", psz_line );
+        if( !strncasecmp( psz_line, "Content-Type:", 13 ) )
+        {
+            p_ch = psz_line + 13;
+            while( *p_ch != '\0' && ( *p_ch == ' ' || *p_ch == '\t' ) ) p_ch++;
+            if( strncasecmp( p_ch, "image/jpeg", 10 ) )
+            {
+                msg_Warn( p_demux, "%s, image/jpeg is expected", psz_line );
+                b_jpeg = VLC_FALSE;
+            }
+            else
+            {
+                b_jpeg = VLC_TRUE;
+            }
+        }
+        else
+        {
+            msg_Dbg( p_demux, "Discard MIME header: %s", psz_line );
+        }
+        free( psz_line );
+        psz_line = GetLine( p_demux, &i_pos );
+    }
+    if( NULL == psz_line )
+    {
+        msg_Err( p_demux, "no EOL" );
+        *p_header_size = -3;
+        return VLC_FALSE;
+    }
+    *p_header_size = i_pos;
+    return b_jpeg;
+}
+
+static int SendBlock( demux_t *p_demux, int i )
+{
+    demux_sys_t *p_sys = p_demux->p_sys;
+    block_t     *p_block;
+
+    if( ( p_block = stream_Block( p_demux->s, i ) ) == NULL )
+    {
+        msg_Warn( p_demux, "cannot read data" );
+        return 0;
+    }
+
+    if( 0 == p_sys->i_frame_length )
+    {
+        p_block->i_dts = p_block->i_pts = mdate() + 1;
+    }
+    else
+    {
+        p_block->i_dts = p_block->i_pts = p_sys->i_time;
+        p_sys->i_time += p_sys->i_frame_length;
+    }
+
+    /* set PCR */
+    es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_block->i_pts );
+    es_out_Send( p_demux->out, p_sys->p_es, p_block );
+    return 1;
+}
+
+/*****************************************************************************
+ * Open: check file and initializes structures
+ *****************************************************************************/
+static int Open( vlc_object_t * p_this )
+{
+    demux_t     *p_demux = (demux_t*)p_this;
+    demux_sys_t *p_sys;
+    int         i_size;
+    int         b_matched = VLC_FALSE;
+    vlc_value_t val;
+    float       f_fps;
+
+    p_demux->pf_control = Control;
+    p_demux->p_sys      = p_sys = malloc( sizeof( demux_sys_t ) );
+    p_sys->p_es         = NULL;
+    p_sys->i_time       = 1;
+    var_Create( p_demux, VAR_FPS, VLC_VAR_FLOAT | VLC_VAR_DOINHERIT );
+    var_Get( p_demux, VAR_FPS, &val );
+    f_fps = val.f_float;
+    p_sys->i_frame_length = 1000000.0 / f_fps;
+    p_sys->psz_separator = NULL;
+    p_sys->i_frame_size_estimate = 15 * 1024;
+
+    b_matched = CheckMimeHeader( p_demux, &i_size);
+    if( b_matched )
+    {
+        p_demux->pf_demux = MimeDemux;
+        stream_Read( p_demux->s, NULL, i_size );
+    }
+    else if( 0 == i_size )
+    {
+        /* 0xffd8 identify a JPEG SOI */
+        if( p_sys->p_peek[0] == 0xFF && p_sys->p_peek[1] == 0xD8 )
+        {
+            msg_Dbg( p_demux, "JPEG SOI marker detected" );
+            p_demux->pf_demux = MjpgDemux;
+        }
+        else
+        {
+            goto error;
+        }
+    }
+    else
+    {
+        goto error;
+    }
+
+    es_format_Init( &p_sys->fmt, VIDEO_ES, 0 );
+    p_sys->fmt.i_codec = VLC_FOURCC('m','j','p','g');
+
+    p_sys->p_es = es_out_Add( p_demux->out, &p_sys->fmt );
+    return VLC_SUCCESS;
+
+error:
+    msg_Warn( p_demux, "JPEG camera module discarded" );
+    free( p_sys );
+    return VLC_EGENERIC;
+}
+
+/*****************************************************************************
+ * Demux: read packet and send them to decoders
+ *****************************************************************************
+ * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
+ *****************************************************************************/
+static int MjpgDemux( demux_t *p_demux )
+{
+    demux_sys_t *p_sys = p_demux->p_sys;
+    int         i;
+
+    if( !Peek( p_demux, VLC_TRUE ) )
+    {
+        msg_Warn( p_demux, "cannot peek data" );
+        return 0;
+    }
+    if( p_sys->i_data_peeked < 4 )
+    {
+        msg_Warn( p_demux, "data shortage" );
+        return 0;
+    }
+    i = 3;
+    while( !( 0xFF == p_sys->p_peek[i-1] && 0xD9 == p_sys->p_peek[i] ) )
+    {
+        i++;
+        if( i >= p_sys->i_data_peeked )
+        {
+            msg_Dbg( p_demux, "Did not find JPEG EOI in %d bytes", p_sys->i_data_peeked );
+            if( !Peek( p_demux, VLC_FALSE ) )
+            {
+                msg_Warn( p_demux, "No more data is available at the moment" );
+                return 0;
+            }
+        }
+    }
+    i++;
+    msg_Dbg( p_demux, "JPEG EOI detected at %d", i );
+    return SendBlock( p_demux, i );
+}
+
+static int MimeDemux( demux_t *p_demux )
+{
+    demux_sys_t *p_sys = p_demux->p_sys;
+    int         i_size, i;
+    vlc_bool_t  b_match;
+    vlc_bool_t  b_done;
+
+    b_match = CheckMimeHeader( p_demux, &i_size );
+    if( i_size > 0 )
+    {
+        stream_Read( p_demux->s, NULL, i_size );
+    }
+    else if( i_size < 0 )
+    {
+        return 0;
+    }
+    else
+    {
+        // No MIME header, assume OK
+        b_match = VLC_TRUE;
+    }
+
+    if( !Peek( p_demux, VLC_TRUE ) )
+    {
+        msg_Warn( p_demux, "cannot peek data" );
+        return 0;
+    }
+    i = 0;
+    i_size = strlen( p_sys->psz_separator ) + 2;
+    if( p_sys->i_data_peeked < i_size )
+    {
+        msg_Warn( p_demux, "data shortage" );
+        return 0;
+    }
+    b_done = VLC_FALSE;
+    while( !b_done )
+    {
+        while( !( p_sys->p_peek[i] == '-' && p_sys->p_peek[i+1] == '-' ) )
+        {
+            i++;
+            i_size++;
+            if( i_size >= p_sys->i_data_peeked )
+            {
+                msg_Dbg( p_demux, "MIME boundary not found in %d bytes of data", p_sys->i_data_peeked );
+                if( !Peek( p_demux, VLC_FALSE ) )
+                {
+                    msg_Warn( p_demux, "No more data is available at the moment" );
+                    return 0;
+                }
+            }
+        }
+        if( !strncmp( p_sys->psz_separator, p_sys->p_peek + i + 2, strlen( p_sys->psz_separator ) ) )
+        {
+            b_done = VLC_TRUE;
+            msg_Dbg( p_demux, "MIME boundary detected at %d", i );
+        }
+        else
+        {
+            i++;
+            i_size++;
+            msg_Dbg( p_demux, "not done" );
+        }
+    }
+
+    msg_Dbg( p_demux, "i is %d", i );  
+    if( !b_match )
+    {
+        msg_Err( p_demux, "Discard non-JPEG part" );
+        stream_Read( p_demux->s, NULL, i );
+        return 0;
+    }
+
+    return SendBlock( p_demux, i );
+}
+
+/*****************************************************************************
+ * Close: frees unused data
+ *****************************************************************************/
+static void Close ( vlc_object_t * p_this )
+{
+    demux_t     *p_demux = (demux_t*)p_this;
+    demux_sys_t *p_sys  = p_demux->p_sys;
+
+    if( p_sys->psz_separator )
+    {
+        free( p_sys->psz_separator );
+    }
+    free( p_sys );
+}
+
+/*****************************************************************************
+ * Control:
+ *****************************************************************************/
+static int Control( demux_t *p_demux, int i_query, va_list args )
+{
+    demux_sys_t *p_sys  = p_demux->p_sys;
+    int64_t i_end = -1;
+    if( p_sys->i_data_size > 0 )
+    {
+        i_end = p_sys->i_data_pos + p_sys->i_data_size;
+    }
+    return demux2_vaControlHelper( p_demux->s,
+                                   p_sys->i_data_pos, i_end,
+                                   p_sys->fmt.i_bitrate, p_sys->fmt.audio.i_blockalign,
+                                   i_query, args );
+}
+
+