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gst/mpeg4videoparse/mpeg4videoparse.*: Improved version not damaging headers using a simple state machine.
Original commit message from CVS: 2007-10-27 Julien MOUTTE <julien@moutte.net> * gst/mpeg4videoparse/mpeg4videoparse.c: (gst_mpeg4vparse_align), (gst_mpeg4vparse_drain), (gst_mpeg4vparse_chain), (gst_mpeg4vparse_sink_setcaps), (gst_mpeg4vparse_sink_event), (gst_mpeg4vparse_cleanup), (gst_mpeg4vparse_change_state), (gst_mpeg4vparse_dispose), (gst_mpeg4vparse_base_init), (gst_mpeg4vparse_class_init), (gst_mpeg4vparse_init), (plugin_init): * gst/mpeg4videoparse/mpeg4videoparse.h: Improved version not damaging headers using a simple state machine.
This commit is contained in:
Julien Moutte
parent
936460ea72
commit
adbe2a1b69
3 changed files with 106 additions and 37 deletions
12
ChangeLog
12
ChangeLog
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@ -1,3 +1,15 @@
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2007-10-27 Julien MOUTTE <julien@moutte.net>
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* gst/mpeg4videoparse/mpeg4videoparse.c: (gst_mpeg4vparse_align),
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(gst_mpeg4vparse_drain), (gst_mpeg4vparse_chain),
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(gst_mpeg4vparse_sink_setcaps), (gst_mpeg4vparse_sink_event),
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(gst_mpeg4vparse_cleanup), (gst_mpeg4vparse_change_state),
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(gst_mpeg4vparse_dispose), (gst_mpeg4vparse_base_init),
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(gst_mpeg4vparse_class_init), (gst_mpeg4vparse_init),
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(plugin_init):
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* gst/mpeg4videoparse/mpeg4videoparse.h: Improved version not
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damaging headers using a simple state machine.
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2007-10-26 Tim-Philipp Müller <tim at centricular dot net>
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* ext/x264/gstx264enc.c:
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@ -51,51 +51,81 @@ GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK,
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GST_BOILERPLATE (GstMpeg4VParse, gst_mpeg4vparse, GstElement, GST_TYPE_ELEMENT);
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static void
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gst_mpeg4vparse_align (GstMpeg4VParse * parse)
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{
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guint flushed = 0;
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/* Searching for a start code */
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while (gst_adapter_available (parse->adapter) >= 4) {
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/* If we have enough data, ensure we're aligned to a start code */
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const guint8 *data = gst_adapter_peek (parse->adapter, 4);
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if (data[0] == 0 && data[1] == 0 && data[2] == 1) {
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GST_LOG_OBJECT (parse, "found start code with type %02X", data[3]);
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parse->state = PARSE_START_FOUND;
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break;
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} else {
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gst_adapter_flush (parse->adapter, 1);
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flushed++;
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parse->state = PARSE_NEED_START;
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}
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}
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if (G_UNLIKELY (flushed)) {
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GST_LOG_OBJECT (parse, "flushed %u bytes while aligning", flushed);
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}
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}
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static GstFlowReturn
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gst_mpeg4vparse_drain (GstMpeg4VParse * parse)
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{
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GstFlowReturn ret = GST_FLOW_OK;
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const guint8 *data = NULL;
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guint i = 0, available = 0;
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guint available = 0;
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while (gst_adapter_available (parse->adapter) >= 4) {
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/* If we have enough data, ensure we're aligned to a start code */
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data = gst_adapter_peek (parse->adapter, 4);
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if (data[0] == 0 && data[1] == 0 && data[2] == 1) {
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GST_LOG_OBJECT (parse, "found start code with type %02X", data[3]);
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parse->found_start = TRUE;
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break;
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} else {
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GST_LOG_OBJECT (parse, "flushing 1 byte");
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gst_adapter_flush (parse->adapter, 1);
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}
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}
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if (G_UNLIKELY (!parse->found_start)) {
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GST_DEBUG_OBJECT (parse, "start code not found, need more data");
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goto beach;
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}
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if (G_UNLIKELY (gst_adapter_available (parse->adapter) < 8)) {
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GST_DEBUG_OBJECT (parse, "start code found, need more data to find next");
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goto beach;
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}
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/* Found a start code, search for the next one */
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available = gst_adapter_available (parse->adapter);
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data = gst_adapter_peek (parse->adapter, available);
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for (i = 4; i < available - 4; i++) {
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/* We generate packets based on VOP start code */
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if (data[i] == 0 && data[i + 1] == 0 && data[i + 2] == 1 &&
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data[i + 3] == 0xB6) {
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GstBuffer *out_buf = gst_adapter_take_buffer (parse->adapter, i);
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GST_LOG_OBJECT (parse, "found next start code at %u", i);
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if (out_buf) {
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gst_buffer_set_caps (out_buf, GST_PAD_CAPS (parse->srcpad));
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gst_pad_push (parse->srcpad, out_buf);
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while (parse->offset < available - 4) {
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/* We generate packets based on VOP end code (next start code) */
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if (data[parse->offset] == 0 && data[parse->offset + 1] == 0 &&
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data[parse->offset + 2] == 1) {
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switch (parse->state) {
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case PARSE_START_FOUND:
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if (data[parse->offset + 3] == 0xB6) {
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GST_LOG_OBJECT (parse, "found VOP start marker at %u",
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parse->offset);
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parse->state = PARSE_VOP_FOUND;
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}
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/* Jump over it */
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parse->offset += 4;
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break;
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case PARSE_VOP_FOUND:
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{ /* We were in a VOP already, any start code marks the end of it */
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GstBuffer *out_buf = gst_adapter_take_buffer (parse->adapter,
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parse->offset);
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GST_LOG_OBJECT (parse, "found VOP end marker at %u", parse->offset);
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if (out_buf) {
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gst_buffer_set_caps (out_buf, GST_PAD_CAPS (parse->srcpad));
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gst_pad_push (parse->srcpad, out_buf);
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}
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/* Restart now that we flushed data */
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parse->offset = 0;
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parse->state = PARSE_START_FOUND;
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available = gst_adapter_available (parse->adapter);
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data = gst_adapter_peek (parse->adapter, available);
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break;
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}
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default:
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GST_WARNING_OBJECT (parse, "unexpected parse state (%d)",
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parse->state);
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ret = GST_FLOW_UNEXPECTED;
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goto beach;
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}
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parse->found_start = FALSE;
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} else { /* Continue searching */
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parse->offset++;
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}
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}
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@ -116,8 +146,27 @@ gst_mpeg4vparse_chain (GstPad * pad, GstBuffer * buffer)
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gst_adapter_push (parse->adapter, buffer);
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/* We need to get aligned on a start code */
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if (G_UNLIKELY (parse->state == PARSE_NEED_START)) {
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gst_mpeg4vparse_align (parse);
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/* No start code found in that buffer */
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if (G_UNLIKELY (parse->state == PARSE_NEED_START)) {
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GST_DEBUG_OBJECT (parse, "start code not found, need more data");
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goto beach;
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}
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}
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/* We need at least 8 bytes to find the next start code which marks the end
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of the one we just found */
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if (G_UNLIKELY (gst_adapter_available (parse->adapter) < 8)) {
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GST_DEBUG_OBJECT (parse, "start code found, need more data to find next");
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goto beach;
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}
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/* Drain the accumulated blocks frame per frame */
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ret = gst_mpeg4vparse_drain (parse);
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beach:
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gst_object_unref (parse);
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return ret;
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@ -176,7 +225,8 @@ gst_mpeg4vparse_cleanup (GstMpeg4VParse * parse)
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gst_adapter_clear (parse->adapter);
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}
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parse->found_start = FALSE;
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parse->state = PARSE_NEED_START;
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parse->offset = 0;
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}
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static GstStateChangeReturn
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@ -40,6 +40,12 @@ G_BEGIN_DECLS
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typedef struct _GstMpeg4VParse GstMpeg4VParse;
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typedef struct _GstMpeg4VParseClass GstMpeg4VParseClass;
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typedef enum {
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PARSE_NEED_START,
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PARSE_START_FOUND,
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PARSE_VOP_FOUND
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} GstMpeg4VParseState;
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struct _GstMpeg4VParse {
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GstElement element;
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@ -47,8 +53,9 @@ struct _GstMpeg4VParse {
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GstPad * srcpad;
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GstAdapter * adapter;
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guint offset;
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gboolean found_start;
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GstMpeg4VParseState state;
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};
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struct _GstMpeg4VParseClass {
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