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flvdemux: Obtain the index from the end of an flv file in push mode

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Allows for better support of seeking in flv files when in push mode
This commit is contained in:
Robert Swain 2010-02-12 16:06:45 +01:00
parent dd23397b4f
commit bf9d8dbbdc
3 changed files with 221 additions and 35 deletions

179
gst/flv/gstflvdemux.c
View file

@ -39,6 +39,7 @@
#include "gstflvmux.h"
#include <string.h>
#include <gst/base/gstbytereader.h>
static GstStaticPadTemplate flv_sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
@ -68,6 +69,9 @@ GST_BOILERPLATE (GstFLVDemux, gst_flv_demux, GstElement, GST_TYPE_ELEMENT);
/* 1 byte of tag type + 3 bytes of tag data size */
#define FLV_TAG_TYPE_SIZE 4
static gboolean flv_demux_handle_seek_push (GstFLVDemux * demux,
GstEvent * event);
static void
gst_flv_demux_flush (GstFLVDemux * demux, gboolean discont)
{
@ -80,8 +84,8 @@ gst_flv_demux_flush (GstFLVDemux * demux, gboolean discont)
demux->flushing = FALSE;
/* Only in push mode */
if (!demux->random_access) {
/* Only in push mode and if we're not during a seek */
if (!demux->random_access && demux->state != FLV_STATE_SEEK) {
/* After a flush we expect a tag_type */
demux->state = FLV_STATE_TAG_TYPE;
/* We reset the offset and will get one from first push */
@ -171,6 +175,29 @@ gst_flv_demux_cleanup (GstFLVDemux * demux)
}
}
/*
* Create and push a flushing seek event upstream
*/
static gboolean
flv_demux_seek_to_offset (GstFLVDemux * demux, guint64 offset)
{
GstEvent *event;
gboolean res = 0;
GST_DEBUG_OBJECT (demux, "Seeking to %" G_GUINT64_FORMAT, offset);
event =
gst_event_new_seek (1.0, GST_FORMAT_BYTES,
GST_SEEK_FLAG_FLUSH | GST_SEEK_FLAG_ACCURATE, GST_SEEK_TYPE_SET, offset,
GST_SEEK_TYPE_NONE, -1);
res = gst_pad_push_event (demux->sinkpad, event);
if (res)
demux->offset = offset;
return res;
}
static GstFlowReturn
gst_flv_demux_chain (GstPad * pad, GstBuffer * buffer)
{
@ -195,6 +222,13 @@ gst_flv_demux_chain (GstPad * pad, GstBuffer * buffer)
gst_adapter_push (demux->adapter, buffer);
if (demux->seeking) {
demux->state = FLV_STATE_SEEK;
GST_OBJECT_LOCK (demux);
demux->seeking = FALSE;
GST_OBJECT_UNLOCK (demux);
}
parse:
if (G_UNLIKELY (ret != GST_FLOW_OK)) {
if (ret == GST_FLOW_NOT_LINKED && (demux->audio_linked
@ -246,6 +280,11 @@ parse:
gst_buffer_unref (buffer);
demux->offset += FLV_TAG_TYPE_SIZE;
/* last tag is not an index => no index/don't know where the index is
* seek back to the beginning */
if (demux->seek_event && demux->state != FLV_STATE_TAG_SCRIPT)
goto no_index;
goto parse;
} else {
goto beach;
@ -300,11 +339,67 @@ parse:
demux->offset += demux->tag_size;
demux->state = FLV_STATE_TAG_TYPE;
/* if there's a seek event we're here for the index so if we don't have it
* we seek back to the beginning */
if (demux->seek_event) {
if (demux->indexed)
demux->state = FLV_STATE_SEEK;
else
goto no_index;
}
goto parse;
} else {
goto beach;
}
}
case FLV_STATE_SEEK:
{
GstEvent *event;
ret = GST_FLOW_OK;
if (!demux->indexed) {
if (demux->offset == demux->file_size - sizeof (guint32)) {
GstBuffer *buffer =
gst_adapter_take_buffer (demux->adapter, sizeof (guint32));
GstByteReader *reader = gst_byte_reader_new_from_buffer (buffer);
guint64 seek_offset;
if (!gst_adapter_available (demux->adapter) >= sizeof (guint32)) {
/* error */
}
seek_offset =
demux->file_size - sizeof (guint32) -
gst_byte_reader_peek_uint32_be_unchecked (reader);
gst_byte_reader_free (reader);
gst_buffer_unref (buffer);
GST_INFO_OBJECT (demux,
"Seeking to beginning of last tag at %" G_GUINT64_FORMAT,
seek_offset);
demux->state = FLV_STATE_TAG_TYPE;
flv_demux_seek_to_offset (demux, seek_offset);
goto beach;
} else
goto no_index;
}
GST_OBJECT_LOCK (demux);
event = demux->seek_event;
demux->seek_event = NULL;
GST_OBJECT_UNLOCK (demux);
/* calculate and perform seek */
if (!flv_demux_handle_seek_push (demux, event))
goto seek_failed;
gst_event_unref (event);
demux->state = FLV_STATE_TAG_TYPE;
goto beach;
}
default:
GST_DEBUG_OBJECT (demux, "unexpected demuxer state");
}
@ -320,6 +415,26 @@ beach:
gst_object_unref (demux);
return ret;
/* ERRORS */
no_index:
{
GST_OBJECT_LOCK (demux);
demux->seeking = FALSE;
gst_event_unref (demux->seek_event);
demux->seek_event = NULL;
GST_OBJECT_UNLOCK (demux);
GST_WARNING_OBJECT (demux,
"failed to find an index, seeking back to beginning");
flv_demux_seek_to_offset (demux, 0);
return GST_FLOW_OK;
}
seek_failed:
{
GST_ELEMENT_ERROR (demux, STREAM, DEMUX, (NULL), ("seek failed"));
return GST_FLOW_ERROR;
}
}
static GstFlowReturn
@ -664,7 +779,7 @@ gst_flv_demux_find_offset (GstFLVDemux * demux, GstSegment * segment)
}
static gboolean
gst_flv_demux_handle_seek_push (GstFLVDemux * demux, GstEvent * event)
flv_demux_handle_seek_push (GstFLVDemux * demux, GstEvent * event)
{
GstFormat format;
GstSeekFlags flags;
@ -746,6 +861,64 @@ wrong_format:
}
}
static gboolean
gst_flv_demux_handle_seek_push (GstFLVDemux * demux, GstEvent * event)
{
if (!demux->indexed) {
guint64 seek_offset;
gboolean building_index;
GstFormat fmt;
GST_OBJECT_LOCK (demux);
/* handle the seek in the chain function */
demux->seeking = TRUE;
demux->state = FLV_STATE_SEEK;
/* copy the event */
if (demux->seek_event)
gst_event_unref (demux->seek_event);
demux->seek_event = gst_event_ref (event);
/* set the building_index flag so that only one thread can setup the
* structures for index seeking. */
building_index = demux->building_index;
if (!building_index) {
demux->building_index = TRUE;
fmt = GST_FORMAT_BYTES;
if (!demux->file_size
&& !gst_pad_query_peer_duration (demux->sinkpad, &fmt,
&demux->file_size)) {
GST_WARNING_OBJECT (demux,
"Cannot obtain file size - %" G_GINT64_FORMAT ", format %u",
demux->file_size, fmt);
GST_OBJECT_UNLOCK (demux);
return FALSE;
}
/* we hope the last tag is a scriptdataobject containing an index
* the size of the last tag is given in the last guint32 bits
* then we seek to the beginning of the tag, parse it and hopefully obtain an index */
seek_offset = demux->file_size - sizeof (guint32);
GST_DEBUG_OBJECT (demux,
"File size obtained, seeking to %" G_GUINT64_FORMAT, seek_offset);
}
GST_OBJECT_UNLOCK (demux);
if (!building_index) {
GST_INFO_OBJECT (demux, "Seeking to last 4 bytes at %" G_GUINT64_FORMAT,
seek_offset);
return flv_demux_seek_to_offset (demux, seek_offset);
}
/* FIXME: we have to always return true so that we don't block the seek
* thread.
* Note: maybe it is OK to return true if we're still building the index */
return TRUE;
}
return flv_demux_handle_seek_push (demux, event);
}
static gboolean
gst_flv_demux_handle_seek_pull (GstFLVDemux * demux, GstEvent * event)
{

7
gst/flv/gstflvdemux.h
View file

@ -44,6 +44,7 @@ typedef enum
FLV_STATE_TAG_VIDEO,
FLV_STATE_TAG_AUDIO,
FLV_STATE_TAG_SCRIPT,
FLV_STATE_SEEK,
FLV_STATE_DONE,
FLV_STATE_NONE
} GstFLVDemuxState;
@ -118,6 +119,12 @@ struct _GstFLVDemux
gboolean flushing;
gboolean no_more_pads;
gboolean seeking;
gboolean building_index;
gboolean indexed; /* TRUE if index is completely built */
gint64 file_size;
GstEvent *seek_event;
};
struct _GstFLVDemuxClass

70
gst/flv/gstflvparse.c
View file

@ -434,6 +434,7 @@ gst_flv_parse_tag_script (GstFLVDemux * demux, GstBuffer * buffer)
GST_ASSOCIATION_FLAG_KEY_UNIT, GST_FORMAT_TIME, time,
GST_FORMAT_BYTES, fileposition, NULL);
}
demux->indexed = TRUE;
}
}
@ -741,16 +742,17 @@ gst_flv_parse_tag_audio (GstFLVDemux * demux, GstBuffer * buffer)
demux->duration < GST_BUFFER_TIMESTAMP (outbuf))
demux->duration = GST_BUFFER_TIMESTAMP (outbuf);
/* Only add audio frames to the index if we have no video
* and if we don't have random access */
if (!demux->has_video && demux->index && !demux->random_access) {
GST_LOG_OBJECT (demux, "adding association %" GST_TIME_FORMAT "-> %"
G_GUINT64_FORMAT, GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (outbuf)),
demux->cur_tag_offset);
/* Only add audio frames to the index if we have no video, if we don't have
* random access and if the index is not yet complete */
if (!demux->has_video && demux->index && !demux->random_access
&& !demux->indexed) {
GST_LOG_OBJECT (demux,
"adding association %" GST_TIME_FORMAT "-> %" G_GUINT64_FORMAT,
GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (outbuf)), demux->cur_tag_offset);
gst_index_add_association (demux->index, demux->index_id,
GST_ASSOCIATION_FLAG_KEY_UNIT,
GST_FORMAT_TIME, GST_BUFFER_TIMESTAMP (outbuf),
GST_FORMAT_BYTES, demux->cur_tag_offset, NULL);
GST_ASSOCIATION_FLAG_KEY_UNIT, GST_FORMAT_TIME,
GST_BUFFER_TIMESTAMP (outbuf), GST_FORMAT_BYTES, demux->cur_tag_offset,
NULL);
}
if (G_UNLIKELY (demux->audio_need_discont)) {
@ -1079,26 +1081,28 @@ gst_flv_parse_tag_video (GstFLVDemux * demux, GstBuffer * buffer)
demux->duration < GST_BUFFER_TIMESTAMP (outbuf))
demux->duration = GST_BUFFER_TIMESTAMP (outbuf);
if (!keyframe) {
GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_DELTA_UNIT);
if (demux->index && !demux->random_access) {
GST_LOG_OBJECT (demux, "adding association %" GST_TIME_FORMAT "-> %"
G_GUINT64_FORMAT, GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (outbuf)),
demux->cur_tag_offset);
gst_index_add_association (demux->index, demux->index_id,
GST_ASSOCIATION_FLAG_NONE,
GST_FORMAT_TIME, GST_BUFFER_TIMESTAMP (outbuf),
GST_FORMAT_BYTES, demux->cur_tag_offset, NULL);
}
} else {
if (demux->index && !demux->random_access) {
GST_LOG_OBJECT (demux, "adding association %" GST_TIME_FORMAT "-> %"
G_GUINT64_FORMAT, GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (outbuf)),
demux->cur_tag_offset);
gst_index_add_association (demux->index, demux->index_id,
GST_ASSOCIATION_FLAG_KEY_UNIT,
GST_FORMAT_TIME, GST_BUFFER_TIMESTAMP (outbuf),
GST_FORMAT_BYTES, demux->cur_tag_offset, NULL);
if (!demux->indexed) {
if (!keyframe) {
GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_DELTA_UNIT);
if (demux->index && !demux->random_access) {
GST_LOG_OBJECT (demux, "adding association %" GST_TIME_FORMAT "-> %"
G_GUINT64_FORMAT, GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (outbuf)),
demux->cur_tag_offset);
gst_index_add_association (demux->index, demux->index_id,
GST_ASSOCIATION_FLAG_NONE,
GST_FORMAT_TIME, GST_BUFFER_TIMESTAMP (outbuf),
GST_FORMAT_BYTES, demux->cur_tag_offset, NULL);
}
} else {
if (demux->index && !demux->random_access) {
GST_LOG_OBJECT (demux, "adding association %" GST_TIME_FORMAT "-> %"
G_GUINT64_FORMAT, GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (outbuf)),
demux->cur_tag_offset);
gst_index_add_association (demux->index, demux->index_id,
GST_ASSOCIATION_FLAG_KEY_UNIT,
GST_FORMAT_TIME, GST_BUFFER_TIMESTAMP (outbuf),
GST_FORMAT_BYTES, demux->cur_tag_offset, NULL);
}
}
}
@ -1231,9 +1235,11 @@ gst_flv_parse_tag_timestamp (GstFLVDemux * demux, GstBuffer * buffer,
ret = pts * GST_MSECOND;
if (demux->index && (type == 9 || (type == 8 && !demux->has_video))) {
GST_LOG_OBJECT (demux, "adding association %" GST_TIME_FORMAT "-> %"
G_GUINT64_FORMAT, GST_TIME_ARGS (ret), demux->offset);
if (demux->index && !demux->indexed && (type == 9 || (type == 8
&& !demux->has_video))) {
GST_LOG_OBJECT (demux,
"adding association %" GST_TIME_FORMAT "-> %" G_GUINT64_FORMAT,
GST_TIME_ARGS (ret), demux->offset);
gst_index_add_association (demux->index, demux->index_id,
(keyframe) ? GST_ASSOCIATION_FLAG_KEY_UNIT : GST_ASSOCIATION_FLAG_NONE,
GST_FORMAT_TIME, ret, GST_FORMAT_BYTES, demux->offset, NULL);