Commit 58fbcf01 authored by Mark Nauwelaerts's avatar Mark Nauwelaerts
Browse files

jpegdec: optimize buffer handling when parsing

Use an adapter to collect incoming data, and use adapter API to scan and peek.

Fixes #583047.
parent a88acc84
......@@ -152,8 +152,7 @@ gst_jpeg_dec_finalize (GObject * object)
jpeg_destroy_decompress (&dec->cinfo);
if (dec->tempbuf)
gst_buffer_unref (dec->tempbuf);
g_object_unref (dec->adapter);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
......@@ -317,89 +316,34 @@ gst_jpeg_dec_init (GstJpegDec * dec)
/* init properties */
dec->idct_method = JPEG_DEFAULT_IDCT_METHOD;
}
static inline gboolean
is_jpeg_start_marker (const guint8 * data)
{
return (data[0] == 0xff && data[1] == 0xd8);
}
static gboolean
gst_jpeg_dec_find_jpeg_header (GstJpegDec * dec)
{
const guint8 *data;
guint size;
data = GST_BUFFER_DATA (dec->tempbuf);
size = GST_BUFFER_SIZE (dec->tempbuf);
g_return_val_if_fail (size >= 2, FALSE);
while (!is_jpeg_start_marker (data) || data[2] != 0xff) {
const guint8 *marker;
GstBuffer *tmp;
guint off;
marker = memchr (data + 1, 0xff, size - 1 - 2);
if (marker == NULL) {
off = size - 1; /* keep last byte */
} else {
off = marker - data;
}
tmp = gst_buffer_create_sub (dec->tempbuf, off, size - off);
gst_buffer_unref (dec->tempbuf);
dec->tempbuf = tmp;
data = GST_BUFFER_DATA (dec->tempbuf);
size = GST_BUFFER_SIZE (dec->tempbuf);
if (size < 2)
return FALSE; /* wait for more data */
}
return TRUE; /* got header */
dec->adapter = gst_adapter_new ();
}
static gboolean
gst_jpeg_dec_ensure_header (GstJpegDec * dec)
{
g_return_val_if_fail (dec->tempbuf != NULL, FALSE);
check_header:
/* we need at least a start marker (0xff 0xd8)
* and an end marker (0xff 0xd9) */
if (GST_BUFFER_SIZE (dec->tempbuf) <= 4) {
GST_DEBUG ("Not enough data");
return FALSE; /* we need more data */
gint av;
gint offset;
av = gst_adapter_available (dec->adapter);
/* we expect at least 4 bytes, first of which start marker */
offset = gst_adapter_masked_scan_uint32 (dec->adapter, 0xffffff00, 0xffd8ff00,
0, av);
if (G_UNLIKELY (offset < 0)) {
GST_DEBUG_OBJECT (dec, "No JPEG header in current buffer");
/* not found */
if (av > 4)
gst_adapter_flush (dec->adapter, av - 4);
return FALSE;
}
if (!is_jpeg_start_marker (GST_BUFFER_DATA (dec->tempbuf))) {
GST_DEBUG ("Not a JPEG header, resyncing to header...");
if (!gst_jpeg_dec_find_jpeg_header (dec)) {
GST_DEBUG ("No JPEG header in current buffer");
return FALSE; /* we need more data */
}
GST_DEBUG ("Found JPEG header");
goto check_header; /* buffer might have changed */
}
GST_DEBUG_OBJECT (dec, "Found JPEG header");
gst_adapter_flush (dec->adapter, offset);
return TRUE;
}
#if 0
static gboolean
gst_jpeg_dec_have_end_marker (GstJpegDec * dec)
{
guint8 *data = GST_BUFFER_DATA (dec->tempbuf);
guint size = GST_BUFFER_SIZE (dec->tempbuf);
return (size > 2 && data && is_jpeg_end_marker (data + size - 2));
}
#endif
static inline gboolean
gst_jpeg_dec_parse_tag_has_entropy_segment (guint8 tag)
{
......@@ -408,103 +352,107 @@ gst_jpeg_dec_parse_tag_has_entropy_segment (guint8 tag)
return FALSE;
}
/* returns image length in bytes if parsed
/* returns image length in bytes if parsed
* successfully, otherwise 0 */
static guint
gst_jpeg_dec_parse_image_data (GstJpegDec * dec)
{
guint8 *start, *data, *end;
guint size;
gboolean resync;
GstAdapter *adapter = dec->adapter;
gint offset, noffset;
size = GST_BUFFER_SIZE (dec->tempbuf);
start = GST_BUFFER_DATA (dec->tempbuf);
end = start + size;
data = start;
size = gst_adapter_available (adapter);
g_return_val_if_fail (is_jpeg_start_marker (data), 0);
/* we expect at least 4 bytes, first of which start marker */
if (gst_adapter_masked_scan_uint32 (adapter, 0xffff0000, 0xffd80000, 0, 4))
return 0;
GST_DEBUG ("Parsing jpeg image data (%u bytes)", size);
GST_DEBUG ("Parse state: offset=%d, resync=%d, entropy len=%d",
dec->parse_offset, dec->parse_resync, dec->parse_entropy_len);
/* resume from state offset (also skips start marker) */
data += (dec->parse_offset ? dec->parse_offset : 2);
/* offset is 2 less than actual offset;
* - adapter needs at least 4 bytes for scanning,
* - start and end marker ensure at least that much
*/
/* resume from state offset */
offset = dec->parse_offset;
while (1) {
guint frame_len;
/* do we need to resync? */
resync = (*data != 0xff);
if (resync) {
GST_DEBUG ("Lost sync at 0x%08" G_GINT64_MODIFIER "x, resyncing",
(gint64) (data - start));
/* at the very least we expect 0xff 0xNN, thus end-1 */
while (*data != 0xff && data < end - 1)
++data;
if (G_UNLIKELY (*data != 0xff)) {
GST_DEBUG ("at end of input and no next marker found, need more data");
goto need_more_data;
}
guint32 value;
noffset =
gst_adapter_masked_scan_uint32_peek (adapter, 0x0000ff00, 0x0000ff00,
offset, size - offset, &value);
/* lost sync if 0xff marker not where expected */
if ((resync = (noffset != offset))) {
GST_DEBUG ("Lost sync at 0x%08x, resyncing", offset + 2);
}
/* may have marker, but could have been resyncng */
resync = resync || dec->parse_resync;
/* Skip over extra 0xff */
while (*data == 0xff && data < end)
++data;
while ((noffset > 0) && ((value & 0xff) == 0xff)) {
noffset++;
noffset =
gst_adapter_masked_scan_uint32_peek (adapter, 0x0000ff00, 0x0000ff00,
noffset, size - noffset, &value);
}
/* enough bytes left for marker? (we need 0xNN after the 0xff) */
if (data >= end) {
if (noffset < 0) {
GST_DEBUG ("at end of input and no EOI marker found, need more data");
goto need_more_data1;
goto need_more_data;
}
if (*data == 0xd9) {
GST_DEBUG ("0x%08" G_GINT64_MODIFIER "x: EOI marker",
(gint64) (data - start));
/* now lock on the marker we found */
offset = noffset;
value = value & 0xff;
if (value == 0xd9) {
GST_DEBUG ("0x%08x: EOI marker", offset + 2);
/* clear parse state */
dec->parse_resync = FALSE;
dec->parse_offset = 0;
return (data - start + 1);
return (offset + 4);
}
if (*data >= 0xd0 && *data <= 0xd7)
if (value >= 0xd0 && value <= 0xd7)
frame_len = 0;
else if (data >= end - 2)
goto need_more_data1;
else
frame_len = GST_READ_UINT16_BE (data + 1);
GST_DEBUG ("0x%08" G_GINT64_MODIFIER "x: tag %02x, frame_len=%u",
(gint64) (data - start - 1), *data, frame_len);
else {
/* peek tag and subsequent length */
if (offset + 2 + 4 > size)
goto need_more_data;
else
gst_adapter_masked_scan_uint32_peek (adapter, 0x0, 0x0, offset + 2, 4,
&frame_len);
frame_len = frame_len & 0xffff;
}
GST_DEBUG ("0x%08x: tag %02x, frame_len=%u", offset + 2, value, frame_len);
/* the frame length includes the 2 bytes for the length; here we want at
* least 2 more bytes at the end for an end marker, thus end-2 */
if (data + 1 + frame_len >= end - 2) {
if (resync) {
GST_DEBUG ("not a valid sync (not enough data).");
/* Since *data != 0xff, the next iteration will go into resync again. */
continue;
}
/* theoretically we could have lost sync and not really need more
* data, but that's just tough luck and a broken image then */
GST_DEBUG ("at end of input and no EOI marker found, need more data");
goto need_more_data1;
* least 2 more bytes at the end for an end marker */
if (offset + 2 + 2 + frame_len + 2 > size) {
goto need_more_data;
}
if (gst_jpeg_dec_parse_tag_has_entropy_segment (*data)) {
guint8 *d2 = data + 1 + frame_len;
if (gst_jpeg_dec_parse_tag_has_entropy_segment (value)) {
guint eseglen = dec->parse_entropy_len;
GST_DEBUG ("0x%08" G_GINT64_MODIFIER "x: finding entropy segment length",
(gint64) (data - start - 1));
GST_DEBUG ("0x%08x: finding entropy segment length", offset + 2);
noffset = offset + 2 + frame_len + dec->parse_entropy_len;
while (1) {
if (d2 + eseglen >= end - 1) {
noffset = gst_adapter_masked_scan_uint32_peek (adapter, 0x0000ff00,
0x0000ff00, noffset, size - noffset, &value);
if (noffset < 0) {
/* need more data */
dec->parse_entropy_len = eseglen;
goto need_more_data1;
dec->parse_entropy_len = size - offset - 4 - frame_len - 2;
goto need_more_data;
}
if (d2[eseglen] == 0xff && d2[eseglen + 1] != 0x00)
if ((value & 0xff) != 0x00) {
eseglen = noffset - offset - frame_len - 2;
break;
++eseglen;
}
noffset++;
}
dec->parse_entropy_len = 0;
frame_len += eseglen;
......@@ -514,28 +462,24 @@ gst_jpeg_dec_parse_image_data (GstJpegDec * dec)
if (resync) {
/* check if we will still be in sync if we interpret
* this as a sync point and skip this frame */
if (data[2 + frame_len] != 0xff) {
noffset = offset + frame_len + 2;
noffset = gst_adapter_masked_scan_uint32 (adapter, 0x0000ff00, 0x0000ff00,
noffset, 4);
if (noffset < 0) {
/* ignore and continue resyncing until we hit the end
* of our data or find a sync point that looks okay */
continue;
}
GST_DEBUG ("found sync at %p", data - size);
GST_DEBUG ("found sync at 0x%x", offset + 2);
}
data += 1 + frame_len;
offset += frame_len + 2;
}
/* EXITS */
need_more_data:
{
dec->parse_offset = data - start;
dec->parse_resync = resync;
return 0;
}
need_more_data1:
{
/* step back one to point at marker */
dec->parse_offset = (data - start) - 1;
dec->parse_offset = offset;
dec->parse_resync = resync;
return 0;
}
......@@ -1188,17 +1132,13 @@ gst_jpeg_dec_chain (GstPad * pad, GstBuffer * buf)
if (GST_BUFFER_IS_DISCONT (buf)) {
GST_DEBUG_OBJECT (dec, "buffer has DISCONT flag set");
dec->discont = TRUE;
if (!dec->packetized && dec->tempbuf != NULL) {
if (!dec->packetized && gst_adapter_available (dec->adapter)) {
GST_WARNING_OBJECT (dec, "DISCONT buffer in non-packetized mode, bad");
gst_buffer_replace (&dec->tempbuf, NULL);
gst_adapter_clear (dec->adapter);
}
}
if (dec->tempbuf) {
dec->tempbuf = gst_buffer_join (dec->tempbuf, buf);
} else {
dec->tempbuf = buf;
}
gst_adapter_push (dec->adapter, buf);
buf = NULL;
/* If we are non-packetized and know the total incoming size in bytes,
......@@ -1206,10 +1146,10 @@ gst_jpeg_dec_chain (GstPad * pad, GstBuffer * buf)
if (!dec->packetized && (dec->segment.format == GST_FORMAT_BYTES) &&
(dec->segment.stop != -1) &&
(GST_BUFFER_SIZE (dec->tempbuf) < dec->segment.stop)) {
(gst_adapter_available (dec->adapter) < dec->segment.stop)) {
/* We assume that non-packetized input in bytes is *one* single jpeg image */
GST_DEBUG ("Non-packetized mode. Got %d bytes, need %" G_GINT64_FORMAT,
GST_BUFFER_SIZE (dec->tempbuf), dec->segment.stop);
gst_adapter_available (dec->adapter), dec->segment.stop);
goto need_more_data;
}
......@@ -1221,7 +1161,7 @@ gst_jpeg_dec_chain (GstPad * pad, GstBuffer * buf)
* do some sanity checking instead of parsing all of
* the jpeg data */
if (dec->packetized) {
img_len = GST_BUFFER_SIZE (dec->tempbuf);
img_len = gst_adapter_available (dec->adapter);
} else {
/* Parse jpeg image to handle jpeg input that
* is not aligned to buffer boundaries */
......@@ -1235,7 +1175,7 @@ gst_jpeg_dec_chain (GstPad * pad, GstBuffer * buf)
if (dec->packetized && !gst_jpeg_dec_do_qos (dec, timestamp))
goto skip_decoding;
data = (guchar *) GST_BUFFER_DATA (dec->tempbuf);
data = (guint8 *) gst_adapter_peek (dec->adapter, img_len);
GST_LOG_OBJECT (dec, "image size = %u", img_len);
dec->jsrc.pub.next_input_byte = data;
......@@ -1454,16 +1394,7 @@ gst_jpeg_dec_chain (GstPad * pad, GstBuffer * buf)
skip_decoding:
done:
if (GST_BUFFER_SIZE (dec->tempbuf) == img_len) {
gst_buffer_unref (dec->tempbuf);
dec->tempbuf = NULL;
} else {
GstBuffer *buf = gst_buffer_create_sub (dec->tempbuf, img_len,
GST_BUFFER_SIZE (dec->tempbuf) - img_len);
gst_buffer_unref (dec->tempbuf);
dec->tempbuf = buf;
}
gst_adapter_flush (dec->adapter, img_len);
exit:
......@@ -1598,6 +1529,10 @@ gst_jpeg_dec_sink_event (GstPad * pad, GstEvent * event)
GST_DEBUG_OBJECT (dec, "Aborting decompress");
jpeg_abort_decompress (&dec->cinfo);
gst_segment_init (&dec->segment, GST_FORMAT_UNDEFINED);
gst_adapter_clear (dec->adapter);
dec->parse_offset = 0;
dec->parse_entropy_len = 0;
dec->parse_resync = FALSE;
gst_jpeg_dec_reset_qos (dec);
break;
case GST_EVENT_NEWSEGMENT:{
......@@ -1700,10 +1635,7 @@ gst_jpeg_dec_change_state (GstElement * element, GstStateChange transition)
switch (transition) {
case GST_STATE_CHANGE_PAUSED_TO_READY:
if (dec->tempbuf) {
gst_buffer_unref (dec->tempbuf);
dec->tempbuf = NULL;
}
gst_adapter_clear (dec->adapter);
gst_jpeg_dec_free_buffers (dec);
break;
default:
......
......@@ -25,6 +25,7 @@
#include <setjmp.h>
#include <gst/gst.h>
#include <gst/video/video.h>
#include <gst/base/gstadapter.h>
/* this is a hack hack hack to get around jpeglib header bugs... */
#ifdef HAVE_STDLIB_H
......@@ -69,7 +70,7 @@ struct _GstJpegDec {
GstPad *sinkpad;
GstPad *srcpad;
GstBuffer *tempbuf;
GstAdapter *adapter;
/* TRUE if each input buffer contains a whole jpeg image */
gboolean packetized;
......
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