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flacparse: don't map buffer multiple times when parsing

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This commit is contained in:
Tim-Philipp Müller 2016-01-05 18:13:06 +00:00
parent 910d75ddaf
commit 6dab3ece07
1 changed files with 21 additions and 34 deletions
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55
gst/audioparsers/gstflacparse.c
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@ -646,29 +646,23 @@ need_more_data:
static gboolean static gboolean
gst_flac_parse_frame_is_valid (GstFlacParse * flacparse, gst_flac_parse_frame_is_valid (GstFlacParse * flacparse,
GstBaseParseFrame * frame, guint * ret) const guint8 * data, gsize size, guint * ret)
{ {
GstBuffer *buffer;
GstMapInfo map;
guint max, remaining; guint max, remaining;
guint i, search_start, search_end; guint i, search_start, search_end;
FrameHeaderCheckReturn header_ret; FrameHeaderCheckReturn header_ret;
guint16 block_size; guint16 block_size;
gboolean suspect_start = FALSE, suspect_end = FALSE; gboolean suspect_start = FALSE, suspect_end = FALSE;
gboolean result = FALSE;
buffer = frame->buffer; if (size < flacparse->min_framesize)
gst_buffer_map (buffer, &map, GST_MAP_READ);
if (map.size < flacparse->min_framesize)
goto need_more; goto need_more;
header_ret = header_ret =
gst_flac_parse_frame_header_is_valid (flacparse, map.data, map.size, TRUE, gst_flac_parse_frame_header_is_valid (flacparse, data, size, TRUE,
&block_size, &suspect_start); &block_size, &suspect_start);
if (header_ret == FRAME_HEADER_INVALID) { if (header_ret == FRAME_HEADER_INVALID) {
*ret = 0; *ret = 0;
goto cleanup; return FALSE;
} }
if (header_ret == FRAME_HEADER_MORE_DATA) if (header_ret == FRAME_HEADER_MORE_DATA)
goto need_more; goto need_more;
@ -676,27 +670,27 @@ gst_flac_parse_frame_is_valid (GstFlacParse * flacparse,
/* mind unknown framesize */ /* mind unknown framesize */
search_start = MAX (2, flacparse->min_framesize); search_start = MAX (2, flacparse->min_framesize);
if (flacparse->max_framesize) if (flacparse->max_framesize)
search_end = MIN (map.size, flacparse->max_framesize + 9 + 2); search_end = MIN (size, flacparse->max_framesize + 9 + 2);
else else
search_end = map.size; search_end = size;
search_end -= 2; search_end -= 2;
remaining = map.size; remaining = size;
for (i = search_start; i < search_end; i++, remaining--) { for (i = search_start; i < search_end; i++, remaining--) {
if ((GST_READ_UINT16_BE (map.data + i) & 0xfffe) != 0xfff8) if ((GST_READ_UINT16_BE (data + i) & 0xfffe) != 0xfff8)
continue; continue;
GST_LOG_OBJECT (flacparse, "possible frame end at offset %d", i); GST_LOG_OBJECT (flacparse, "possible frame end at offset %d", i);
suspect_end = FALSE; suspect_end = FALSE;
header_ret = header_ret =
gst_flac_parse_frame_header_is_valid (flacparse, map.data + i, gst_flac_parse_frame_header_is_valid (flacparse, data + i,
remaining, FALSE, NULL, &suspect_end); remaining, FALSE, NULL, &suspect_end);
if (header_ret == FRAME_HEADER_VALID) { if (header_ret == FRAME_HEADER_VALID) {
if (flacparse->check_frame_checksums || suspect_start || suspect_end) { if (flacparse->check_frame_checksums || suspect_start || suspect_end) {
guint16 actual_crc = gst_flac_calculate_crc16 (map.data, i - 2); guint16 actual_crc = gst_flac_calculate_crc16 (data, i - 2);
guint16 expected_crc = GST_READ_UINT16_BE (map.data + i - 2); guint16 expected_crc = GST_READ_UINT16_BE (data + i - 2);
GST_LOG_OBJECT (flacparse, GST_LOG_OBJECT (flacparse,
"Found possible frame (%d, %d). Checking for CRC match", "Found possible frame (%d, %d). Checking for CRC match",
@ -710,8 +704,7 @@ gst_flac_parse_frame_is_valid (GstFlacParse * flacparse,
} }
*ret = i; *ret = i;
flacparse->block_size = block_size; flacparse->block_size = block_size;
result = TRUE; return TRUE;
goto cleanup;
} else if (header_ret == FRAME_HEADER_MORE_DATA) { } else if (header_ret == FRAME_HEADER_MORE_DATA) {
goto need_more; goto need_more;
} }
@ -720,20 +713,18 @@ gst_flac_parse_frame_is_valid (GstFlacParse * flacparse,
/* For the last frame output everything to the end */ /* For the last frame output everything to the end */
if (G_UNLIKELY (GST_BASE_PARSE_DRAINING (flacparse))) { if (G_UNLIKELY (GST_BASE_PARSE_DRAINING (flacparse))) {
if (flacparse->check_frame_checksums) { if (flacparse->check_frame_checksums) {
guint16 actual_crc = gst_flac_calculate_crc16 (map.data, map.size - 2); guint16 actual_crc = gst_flac_calculate_crc16 (data, size - 2);
guint16 expected_crc = GST_READ_UINT16_BE (map.data + map.size - 2); guint16 expected_crc = GST_READ_UINT16_BE (data + size - 2);
if (actual_crc == expected_crc) { if (actual_crc == expected_crc) {
*ret = map.size; *ret = size;
flacparse->block_size = block_size; flacparse->block_size = block_size;
result = TRUE; return TRUE;
goto cleanup;
} }
} else { } else {
*ret = map.size; *ret = size;
flacparse->block_size = block_size; flacparse->block_size = block_size;
result = TRUE; return TRUE;
goto cleanup;
} }
} }
@ -750,12 +741,8 @@ need_more:
max = flacparse->max_framesize + 16; max = flacparse->max_framesize + 16;
if (max == 16) if (max == 16)
max = 1 << 24; max = 1 << 24;
*ret = MIN (map.size + 4096, max); *ret = MIN (size + 4096, max);
result = TRUE; return TRUE;
cleanup:
gst_buffer_unmap (buffer, &map);
return result;
} }
static GstFlowReturn static GstFlowReturn
@ -815,7 +802,7 @@ gst_flac_parse_handle_frame (GstBaseParse * parse,
flacparse->sample_number = 0; flacparse->sample_number = 0;
GST_DEBUG_OBJECT (flacparse, "Found sync code"); GST_DEBUG_OBJECT (flacparse, "Found sync code");
ret = gst_flac_parse_frame_is_valid (flacparse, frame, &next); ret = gst_flac_parse_frame_is_valid (flacparse, map.data, map.size, &next);
if (ret) { if (ret) {
framesize = next; framesize = next;
goto cleanup; goto cleanup;