commit 3a10e7b630e4c5e6f7c534e7f762fbb733a03ab3
parent ac15ab4bc2928e9cfbbcd53dce67d3aa80034dda
Author: Christian Grothoff <christian@grothoff.org>
Date: Tue, 25 Sep 2012 13:57:45 +0000
documenting the code a bit
Diffstat:
1 file changed, 297 insertions(+), 99 deletions(-)
diff --git a/src/plugins/gstreamer_extractor.c b/src/plugins/gstreamer_extractor.c
@@ -757,61 +757,181 @@ struct NamedTag named_tags[] =
};
+/**
+ *
+ */
enum CurrentStreamType
{
+ /**
+ *
+ */
STREAM_TYPE_NONE = 0,
+
+ /**
+ *
+ */
STREAM_TYPE_AUDIO = 1,
+
+ /**
+ *
+ */
STREAM_TYPE_VIDEO = 2,
+
+ /**
+ *
+ */
STREAM_TYPE_SUBTITLE = 3,
+
+ /**
+ *
+ */
STREAM_TYPE_CONTAINER = 4,
+
+ /**
+ *
+ */
STREAM_TYPE_IMAGE = 5
};
+/**
+ * Closure we pass when processing a request.
+ */
struct PrivStruct
{
+ /**
+ * Tracks the time from the last IO request so that we can decide
+ * to terminate processing if GStreamer just takes far too long.
+ * Values are based on 'g_get_monotonic_time()', in milliseconds.
+ */
+ gint64 last_data_request_time;
+
+ /**
+ * Current read-offset in the 'ec' context (based on our read/seek calls).
+ */
+ guint64 offset;
+
+ /**
+ * Overall size of the file we're processing, UINT64_MAX if unknown.
+ */
+ uint64_t length;
+
+ /**
+ *
+ */
GstElement *source;
+
+ /**
+ * Extraction context for IO on the underlying data.
+ */
struct EXTRACTOR_ExtractContext *ec;
- long length;
- guint64 offset;
- int toc_depth;
- size_t toc_length;
- size_t toc_pos;
- gchar *toc;
- gboolean toc_print_phase;
- unsigned char time_to_leave;
- enum CurrentStreamType st;
+
+ /**
+ * Glib main loop.
+ */
GMainLoop *loop;
+
+ /**
+ * Discoverer object we are using.
+ */
GstDiscoverer *dc;
+
+ /**
+ * Location for building the XML 'table of contents' (EXTRACTOR_METATYPE_TOC) for
+ * the input. Used only during 'send_info'.
+ */
+ gchar *toc;
+
+ /**
+ * Length of the 'toc' string.
+ */
+ size_t toc_length;
+
+ /**
+ * Current position (used when creating the 'toc' string).
+ */
+ size_t toc_pos;
+
+ /**
+ *
+ */
guint timeout_id;
- gint64 last_data_request_time;
+
+ /**
+ * Counter used to determine our current depth in the TOC hierarchy.
+ */
+ int toc_depth;
+
+ /**
+ *
+ */
+ enum CurrentStreamType st;
+
+ /**
+ * Last return value from the meta data processor. Set to
+ * 1 to abort, 0 to continue extracting.
+ */
+ int time_to_leave;
+
+ /**
+ * TOC generation is executed in two phases. First phase determines
+ * the size of the string and the second phase actually does the
+ * 'printing' (string construction). This bit is TRUE if we are
+ * in the 'printing' phase.
+ */
+ gboolean toc_print_phase;
+
};
+/**
+ *
+ */
static GQuark *audio_quarks;
+/**
+ *
+ */
static GQuark *video_quarks;
+/**
+ *
+ */
static GQuark *subtitle_quarks;
+/**
+ *
+ */
static GQuark duration_quark;
+/**
+ * Implementation of GstElement's "need-data" callback. Reads data from
+ * the extraction context and passes it to GStreamer.
+ *
+ * @param appsrc the GstElement for which we are implementing "need-data"
+ * @param size number of bytes requested
+ * @param ps our execution context
+ */
static void
-feed_data (GstElement * appsrc, guint size, struct PrivStruct * ps)
+feed_data (GstElement * appsrc,
+ guint size,
+ struct PrivStruct * ps)
{
- long data_len;
+ ssize_t data_len;
uint8_t *le_data;
guint accumulated;
GstMemory *mem;
GstMapInfo mi;
+ GstBuffer *buffer;
GST_DEBUG ("Request %u bytes", size);
/* Update it now, in case we bail out due to error */
ps->last_data_request_time = g_get_monotonic_time ();
- if (ps->length > 0 && ps->offset >= ps->length) {
+ if ( (ps->length > 0) && (ps->offset >= ps->length) )
+ {
/* we are at the EOS, send end-of-stream */
gst_app_src_end_of_stream (GST_APP_SRC (ps->source));
return;
@@ -831,7 +951,7 @@ feed_data (GstElement * appsrc, guint size, struct PrivStruct * ps)
accumulated = 0;
data_len = 1;
- while (accumulated < size && data_len > 0)
+ while ( (accumulated < size) && (data_len > 0) )
{
data_len = ps->ec->read (ps->ec->cls, (void **) &le_data, size - accumulated);
if (data_len > 0)
@@ -841,9 +961,8 @@ feed_data (GstElement * appsrc, guint size, struct PrivStruct * ps)
}
}
gst_memory_unmap (mem, &mi);
- if (data_len > 0)
+ if (size == accumulated)
{
- GstBuffer *buffer;
buffer = gst_buffer_new ();
gst_buffer_append_memory (buffer, mem);
@@ -851,8 +970,8 @@ feed_data (GstElement * appsrc, guint size, struct PrivStruct * ps)
GST_BUFFER_OFFSET (buffer) = ps->offset;
GST_BUFFER_OFFSET_END (buffer) = ps->offset + size;
- GST_DEBUG ("feed buffer %p, offset %" G_GUINT64_FORMAT "-%u", buffer,
- ps->offset, size);
+ GST_DEBUG ("feed buffer %p, offset %" G_GUINT64_FORMAT "-%u",
+ buffer, ps->offset, size);
gst_app_src_push_buffer (GST_APP_SRC (ps->source), buffer);
ps->offset += size;
}
@@ -860,33 +979,43 @@ feed_data (GstElement * appsrc, guint size, struct PrivStruct * ps)
{
gst_memory_unref (mem);
gst_app_src_end_of_stream (GST_APP_SRC (ps->source));
+ ps->offset = UINT64_MAX; /* set to invalid value */
}
/* Update it again to account for time we spent fulfilling the request */
ps->last_data_request_time = g_get_monotonic_time ();
- return;
}
+/**
+ * Implementation of GstElement's "seek-data" callback. Seeks to a new
+ * position in the extraction context.
+ *
+ * @param appsrc the GstElement for which we are implementing "need-data"
+ * @param position new desired absolute position in the file
+ * @param ps our execution context
+ * @return TRUE if seeking succeeded, FALSE if not
+ */
static gboolean
-seek_data (GstElement * appsrc, guint64 position, struct PrivStruct * ps)
+seek_data (GstElement * appsrc,
+ guint64 position,
+ struct PrivStruct * ps)
{
GST_DEBUG ("seek to offset %" G_GUINT64_FORMAT, position);
ps->offset = ps->ec->seek (ps->ec->cls, position, SEEK_SET);
-
ps->last_data_request_time = g_get_monotonic_time ();
- return ps->offset >= 0;
-}
-
-
-static gboolean
-_run_async (struct PrivStruct * ps)
-{
- gst_discoverer_discover_uri_async (ps->dc, "appsrc://");
- return FALSE;
+ return ps->offset == position;
}
+/**
+ * FIXME
+ *
+ * @param field_id FIXME
+ * @param value FIXME
+ * @param user_data our 'struct PrivStruct'
+ * @return TRUE to continue processing, FALSE to abort
+ */
static gboolean
send_structure_foreach (GQuark field_id,
const GValue *value,
@@ -922,7 +1051,6 @@ send_structure_foreach (GQuark field_id,
break;
}
-
switch (G_VALUE_TYPE (value))
{
case G_TYPE_STRING:
@@ -948,7 +1076,7 @@ send_structure_foreach (GQuark field_id,
str = NULL;
break;
}
- if (NULL != str)
+ if (NULL != str)
{
unsigned int i;
@@ -969,16 +1097,24 @@ send_structure_foreach (GQuark field_id,
gchar *senddata = g_strdup_printf ("%s=%s", field_name, str);
ps->time_to_leave = ps->ec->proc (ps->ec->cls, "gstreamer",
EXTRACTOR_METATYPE_UNKNOWN, EXTRACTOR_METAFORMAT_UTF8, "text/plain",
- (const char *) senddata, strlen (senddata) + 1);
+ (const char *) senddata,
+ strlen (senddata) + 1);
g_free (senddata);
}
g_free (str);
- return !ps->time_to_leave;
+ return ! ps->time_to_leave;
}
-static int
+/**
+ * FIXME
+ *
+ * @param info FIXME
+ * @param ps processing context
+ * @return FALSE to continue processing, TRUE to abort
+ */
+static gboolean
send_audio_info (GstDiscovererAudioInfo *info,
struct PrivStruct *ps)
{
@@ -1059,15 +1195,24 @@ send_audio_info (GstDiscovererAudioInfo *info,
}
+/**
+ * FIXME
+ *
+ * @param info FIXME
+ * @param ps processing context
+ * @return FALSE to continue processing, TRUE to abort
+ */
static int
-send_video_info (GstDiscovererVideoInfo *info, struct PrivStruct *ps)
+send_video_info (GstDiscovererVideoInfo *info,
+ struct PrivStruct *ps)
{
gchar *tmp;
- guint u, u2;
+ guint u;
+ guint u2;
u = gst_discoverer_video_info_get_width (info);
u2 = gst_discoverer_video_info_get_height (info);
- if (u > 0 && u2 > 0)
+ if ( (u > 0) && (u2 > 0) )
{
tmp = g_strdup_printf ("%ux%u", u, u2);
ps->time_to_leave = ps->ec->proc (ps->ec->cls, "gstreamer",
@@ -1092,7 +1237,7 @@ send_video_info (GstDiscovererVideoInfo *info, struct PrivStruct *ps)
u = gst_discoverer_video_info_get_framerate_num (info);
u2 = gst_discoverer_video_info_get_framerate_denom (info);
- if (u > 0 && u2 > 0)
+ if ( (u > 0) && (u2 > 0) )
{
tmp = g_strdup_printf ("%u/%u", u, u2);
ps->time_to_leave = ps->ec->proc (ps->ec->cls, "gstreamer",
@@ -1105,7 +1250,7 @@ send_video_info (GstDiscovererVideoInfo *info, struct PrivStruct *ps)
u = gst_discoverer_video_info_get_par_num (info);
u2 = gst_discoverer_video_info_get_par_denom (info);
- if (u > 0 && u2 > 0)
+ if ( (u > 0) && (u2 > 0) )
{
tmp = g_strdup_printf ("%u/%u", u, u2);
ps->time_to_leave = ps->ec->proc (ps->ec->cls, "gstreamer",
@@ -1119,7 +1264,7 @@ send_video_info (GstDiscovererVideoInfo *info, struct PrivStruct *ps)
/* gst_discoverer_video_info_is_interlaced (info) I don't trust it... */
u = gst_discoverer_video_info_get_bitrate (info);
- if (u > 0 && u2 > 0)
+ if (u > 0)
{
tmp = g_strdup_printf ("%u", u);
ps->time_to_leave = ps->ec->proc (ps->ec->cls, "gstreamer",
@@ -1131,7 +1276,7 @@ send_video_info (GstDiscovererVideoInfo *info, struct PrivStruct *ps)
}
u = gst_discoverer_video_info_get_max_bitrate (info);
- if (u > 0 && u2 > 0)
+ if (u > 0)
{
tmp = g_strdup_printf ("%u", u);
ps->time_to_leave = ps->ec->proc (ps->ec->cls, "gstreamer",
@@ -1146,18 +1291,27 @@ send_video_info (GstDiscovererVideoInfo *info, struct PrivStruct *ps)
}
+/**
+ * FIXME
+ *
+ * @param info FIXME
+ * @param ps processing context
+ * @return FALSE to continue processing, TRUE to abort
+ */
static int
-send_subtitle_info (GstDiscovererSubtitleInfo *info, struct PrivStruct *ps)
+send_subtitle_info (GstDiscovererSubtitleInfo *info,
+ struct PrivStruct *ps)
{
const gchar *ctmp;
ctmp = gst_discoverer_subtitle_info_get_language (info);
- if (ctmp)
- if ((ps->time_to_leave = ps->ec->proc (ps->ec->cls, "gstreamer",
- EXTRACTOR_METATYPE_SUBTITLE_LANGUAGE, EXTRACTOR_METAFORMAT_UTF8, "text/plain",
- (const char *) ctmp, strlen (ctmp) + 1)))
- return TRUE;
-
+ if ( (NULL != ctmp) &&
+ (0 != (ps->time_to_leave = ps->ec->proc (ps->ec->cls, "gstreamer",
+ EXTRACTOR_METATYPE_SUBTITLE_LANGUAGE,
+ EXTRACTOR_METAFORMAT_UTF8,
+ "text/plain",
+ (const char *) ctmp, strlen (ctmp) + 1))) )
+ return TRUE;
return FALSE;
}
@@ -1167,11 +1321,11 @@ send_tag_foreach (const GstTagList * tags,
const gchar * tag,
gpointer user_data)
{
+ static struct KnownTag unknown_tag = {NULL, EXTRACTOR_METATYPE_UNKNOWN};
struct PrivStruct *ps = user_data;
size_t i;
size_t tagl = sizeof (__known_tags) / sizeof (struct KnownTag);
- struct KnownTag *kt = NULL;
- struct KnownTag unknown_tag = {NULL, EXTRACTOR_METATYPE_UNKNOWN};
+ const struct KnownTag *kt = NULL;
GQuark tag_quark;
guint vallen;
GstSample *sample;
@@ -1517,12 +1671,13 @@ send_stream_info (GstDiscovererStreamInfo * info,
static void
-send_streams (GstDiscovererStreamInfo *info, struct PrivStruct *ps)
+send_streams (GstDiscovererStreamInfo *info,
+ struct PrivStruct *ps)
{
+ GstDiscovererStreamInfo *next;
+
while ( (NULL != info) && (! ps->time_to_leave) )
{
- GstDiscovererStreamInfo *next;
-
send_stream_info (info, ps);
next = gst_discoverer_stream_info_get_next (info);
gst_discoverer_stream_info_unref (info);
@@ -1531,6 +1686,13 @@ send_streams (GstDiscovererStreamInfo *info, struct PrivStruct *ps)
}
+/**
+ * Callback used to construct the XML 'toc'.
+ *
+ * @param tags FIXME
+ * @param tag FIXME
+ * @param user_data the 'struct PrivStruct' with the 'toc' string we are assembling
+ */
static void
send_toc_tags_foreach (const GstTagList * tags,
const gchar * tag,
@@ -1588,6 +1750,12 @@ send_toc_tags_foreach (const GstTagList * tags,
}
+/**
+ * Top-level callback used to construct the XML 'toc'.
+ *
+ * @param data the GstTocEntry we're processing
+ * @param user_data the 'struct PrivStruct' with the 'toc' string we are assembling
+ */
static void
send_toc_foreach (gpointer data, gpointer user_data)
{
@@ -1595,68 +1763,72 @@ send_toc_foreach (gpointer data, gpointer user_data)
struct PrivStruct *ps = user_data;
GstTagList *tags;
GList *subentries;
- gint64 start, stop;
+ gint64 start;
+ gint64 stop;
GstTocEntryType entype;
+ gchar *s;
entype = gst_toc_entry_get_entry_type (entry);
- if (GST_TOC_ENTRY_TYPE_INVALID != entype)
- {
- char *s;
-
- gst_toc_entry_get_start_stop_times (entry, &start, &stop);
- s = g_strdup_printf ("%*.*s<%s start=\"%" GST_TIME_FORMAT "\" stop=\"%"
- GST_TIME_FORMAT"\">\n", ps->toc_depth * 2, ps->toc_depth * 2, " ",
- gst_toc_entry_type_get_nick (entype), GST_TIME_ARGS (start),
- GST_TIME_ARGS (stop));
- if (ps->toc_print_phase)
- ps->toc_pos += g_snprintf (&ps->toc[ps->toc_pos], ps->toc_length - ps->toc_pos, "%s", s);
- else
- ps->toc_length += strlen (s);
- g_free (s);
- ps->toc_depth++;
- tags = gst_toc_entry_get_tags (entry);
- if (tags)
+ if (GST_TOC_ENTRY_TYPE_INVALID == entype)
+ return;
+ gst_toc_entry_get_start_stop_times (entry, &start, &stop);
+ s = g_strdup_printf ("%*.*s<%s start=\"%" GST_TIME_FORMAT "\" stop=\"%"
+ GST_TIME_FORMAT"\">\n", ps->toc_depth * 2, ps->toc_depth * 2, " ",
+ gst_toc_entry_type_get_nick (entype), GST_TIME_ARGS (start),
+ GST_TIME_ARGS (stop));
+ if (ps->toc_print_phase)
+ ps->toc_pos += g_snprintf (&ps->toc[ps->toc_pos], ps->toc_length - ps->toc_pos, "%s", s);
+ else
+ ps->toc_length += strlen (s);
+ g_free (s);
+ ps->toc_depth++;
+ tags = gst_toc_entry_get_tags (entry);
+ if (tags)
{
if (ps->toc_print_phase)
ps->toc_pos += g_snprintf (&ps->toc[ps->toc_pos], ps->toc_length - ps->toc_pos,
- "%*.*s<tags>\n", ps->toc_depth * 2, ps->toc_depth * 2, " ");
+ "%*.*s<tags>\n", ps->toc_depth * 2, ps->toc_depth * 2, " ");
else
ps->toc_length += strlen ("<tags>\n") + ps->toc_depth * 2;
ps->toc_depth++;
- gst_tag_list_foreach (tags, send_toc_tags_foreach, ps);
+ gst_tag_list_foreach (tags, &send_toc_tags_foreach, ps);
ps->toc_depth--;
if (ps->toc_print_phase)
ps->toc_pos += g_snprintf (&ps->toc[ps->toc_pos], ps->toc_length - ps->toc_pos,
- "%*.*s</tags>\n", ps->toc_depth * 2, ps->toc_depth * 2, " ");
+ "%*.*s</tags>\n", ps->toc_depth * 2, ps->toc_depth * 2, " ");
else
ps->toc_length += strlen ("</tags>\n") + ps->toc_depth * 2;
}
-
- subentries = gst_toc_entry_get_sub_entries (entry);
- g_list_foreach (subentries, send_toc_foreach, ps);
- ps->toc_depth--;
-
- s = g_strdup_printf ("%*.*s</%s>\n", ps->toc_depth * 2, ps->toc_depth * 2, " ",
- gst_toc_entry_type_get_nick (entype));
- if (ps->toc_print_phase)
- ps->toc_pos += g_snprintf (&ps->toc[ps->toc_pos], ps->toc_length - ps->toc_pos, "%s", s);
- else
- ps->toc_length += strlen (s);
- g_free (s);
- }
+
+ subentries = gst_toc_entry_get_sub_entries (entry);
+ g_list_foreach (subentries, send_toc_foreach, ps);
+ ps->toc_depth--;
+
+ s = g_strdup_printf ("%*.*s</%s>\n", ps->toc_depth * 2, ps->toc_depth * 2, " ",
+ gst_toc_entry_type_get_nick (entype));
+ if (ps->toc_print_phase)
+ ps->toc_pos += g_snprintf (&ps->toc[ps->toc_pos], ps->toc_length - ps->toc_pos, "%s", s);
+ else
+ ps->toc_length += strlen (s);
+ g_free (s);
}
+/**
+ * XML header for the table-of-contents meta data.
+ */
#define TOC_XML_HEADER "<?xml version=\"1.0\" encoding=\"UTF-8\" ?>\n"
static void
-send_info (GstDiscovererInfo * info, struct PrivStruct *ps)
+send_info (GstDiscovererInfo * info,
+ struct PrivStruct *ps)
{
const GstToc *toc;
gchar *s;
GstDiscovererStreamInfo *sinfo;
GstClockTime duration;
+ GList *entries;
duration = gst_discoverer_info_get_duration (info);
if ((GST_CLOCK_TIME_IS_VALID (duration)) && (duration > 0))
@@ -1684,12 +1856,10 @@ send_info (GstDiscovererInfo * info, struct PrivStruct *ps)
if ((toc = gst_discoverer_info_get_toc (info)))
{
- GList *entries;
-
entries = gst_toc_get_entries (toc);
ps->toc_print_phase = FALSE;
ps->toc_length = 0;
- g_list_foreach (entries, send_toc_foreach, ps);
+ g_list_foreach (entries, &send_toc_foreach, ps);
if (ps->toc_length > 0)
{
@@ -1697,18 +1867,24 @@ send_info (GstDiscovererInfo * info, struct PrivStruct *ps)
ps->toc_length += 1 + strlen (TOC_XML_HEADER);
ps->toc = g_malloc (ps->toc_length);
ps->toc_pos = 0;
- ps->toc_pos += g_snprintf (&ps->toc[ps->toc_pos], ps->toc_length - ps->toc_pos, "%s", TOC_XML_HEADER);
- g_list_foreach (entries, send_toc_foreach, ps);
+ ps->toc_pos += g_snprintf (&ps->toc[ps->toc_pos],
+ ps->toc_length - ps->toc_pos,
+ "%s",
+ TOC_XML_HEADER);
+ g_list_foreach (entries, &send_toc_foreach, ps);
ps->toc[ps->toc_length - 1] = '\0';
ps->time_to_leave = ps->ec->proc (ps->ec->cls, "gstreamer",
- EXTRACTOR_METATYPE_TOC, EXTRACTOR_METAFORMAT_C_STRING, "application/xml",
- (const char *) ps->toc, ps->toc_length);
+ EXTRACTOR_METATYPE_TOC,
+ EXTRACTOR_METAFORMAT_C_STRING,
+ "application/xml",
+ (const char *) ps->toc,
+ ps->toc_length);
g_free (ps->toc);
ps->toc = NULL;
}
}
- if (ps->time_to_leave)
+ if (0 != ps->time_to_leave)
return;
sinfo = gst_discoverer_info_get_stream_info (info);
@@ -1717,7 +1893,8 @@ send_info (GstDiscovererInfo * info, struct PrivStruct *ps)
static void
-send_discovered_info (GstDiscovererInfo * info, struct PrivStruct * ps)
+send_discovered_info (GstDiscovererInfo * info,
+ struct PrivStruct * ps)
{
GstDiscovererResult result;
@@ -1765,6 +1942,7 @@ _discoverer_finished (GstDiscoverer * dc, struct PrivStruct *ps)
g_main_loop_quit (ps->loop);
}
+
static gboolean
_data_timeout (struct PrivStruct *ps)
{
@@ -1780,11 +1958,17 @@ _data_timeout (struct PrivStruct *ps)
return TRUE;
}
+
/**
* This callback is called when discoverer has constructed a source object to
* read from. Since we provided the appsrc:// uri to discoverer, this will be
* the appsrc that we must handle. We set up some signals - one to push data
- * into appsrc and one to perform a seek. */
+ * into appsrc and one to perform a seek.
+ *
+ * @param dc
+ * @param source
+ * @param ps
+ */
static void
_source_setup (GstDiscoverer * dc,
GstElement * source,
@@ -1816,6 +2000,20 @@ _source_setup (GstDiscoverer * dc,
/**
+ * Task run from the main loop to call 'gst_discoverer_uri_async'.
+ *
+ * @param ps our execution context
+ * @return FALSE (always)
+ */
+static gboolean
+_run_async (struct PrivStruct * ps)
+{
+ gst_discoverer_discover_uri_async (ps->dc, "appsrc://");
+ return FALSE;
+}
+
+
+/**
* This will be the main method of your plugin.
* Describe a bit what it does here.
*
