On 03/03/2015 02:03 AM, Luca Barbato wrote:
On 03/03/15 00:15, Thomas Volkert wrote:
+ has_pic_id = buf[0] & 0x80;
+ has_layer_idc = buf[0] & 0x40;
+ has_ref_idc = buf[0] & 0x20;
+ first_fragment = buf[0] & 0x10;
+ last_fragment = buf[0] & 0x08;
+ has_ss_data = buf[0] & 0x04;
+ has_su_data = buf[0] & 0x02;
+
if they are flags
flag = !!(buf[0] & mask);
might be nicer.
Okay.
+ /* sanity check for markers: B should always be equal to the RTP M marker
*/
+ if (last_fragment >> 2 != flags & RTP_FLAG_MARKER) {
+ av_log(ctx, AV_LOG_ERROR, "Invalid combination of B and M marker\n");
+ return AVERROR_INVALIDDATA;
+ }
Might be night to print B and M here.
Okay.
+
+ /* pass the extensions field */
+ buf += RTP_VP9_DESC_REQUIRED_SIZE;
+ len -= RTP_VP9_DESC_REQUIRED_SIZE;
+
+ /*
+ * decode the 1-byte/2-byte picture ID:
+ *
+ * 0 1 2 3 4 5 6 7
+ * +-+-+-+-+-+-+-+-+
+ * I: |M|PICTURE ID | (RECOMMENDED)
+ * +-+-+-+-+-+-+-+-+
+ * M: | EXTENDED PID | (RECOMMENDED)
+ * +-+-+-+-+-+-+-+-+
+ *
+ * M: The most significant bit of the first octet is an extension flag.
+ * PictureID: 8 or 16 bits including the M bit.
+ */
+ if (has_pic_id) {
+ if (len < 1) {
+ av_log(ctx, AV_LOG_ERROR, "Too short RTP/VP9 packet\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ /* check for 1-byte or 2-byte picture index */
+ if (buf[0] & 0x80) {
+ if (len < 2) {
+ av_log(ctx, AV_LOG_ERROR, "Too short RTP/VP9 packet\n");
+ return AVERROR_INVALIDDATA;
+ }
+ pic_id = AV_RB16(buf) & 0x7fff;
+ buf += 2;
+ len -= 2;
+ } else {
+ pic_id = buf[0] & 0x7f;
+ buf++;
+ len--;
+ }
+ }
+
+ /*
+ * decode layer indices
+ *
+ * 0 1 2 3 4 5 6 7
+ * +-+-+-+-+-+-+-+-+
+ * L: | T | S | Q | R | (CONDITIONALLY RECOMMENDED)
+ * +-+-+-+-+-+-+-+-+
+ *
+ * T, S and Q are 2-bit indices for temporal, spatial, and quality
layers.
+ * If "F" is set in the initial octet, R is 2 bits representing the
number
+ * of reference fields this frame refers to.
+ */
+ if (has_layer_idc) {
+ if (len < 1) {
+ av_log(ctx, AV_LOG_ERROR, "Too short RTP/VP9 packet");
+ return AVERROR_INVALIDDATA;
+ }
+ layer_temporal = buf[0] & 0xC0;
+ layer_spatial = buf[0] & 0x30;
+ layer_quality = buf[0] & 0x0C;
+ if (has_ref_idc) {
+ ref_fields = buf[0] & 0x03;
+ if (ref_fields)
+ non_key_frame = 1;
+ }
+ buf++;
+ len--;
+ }
+
+ /*
+ * decode the reference fields
+ *
+ * 0 1 2 3 4 5 6 7
+ * +-+-+-+-+-+-+-+-+ -\
+ * F: | PID |X| RS| RQ| (OPTIONAL) .
+ * +-+-+-+-+-+-+-+-+ . - R times
+ * X: | EXTENDED PID | (OPTIONAL) .
+ * +-+-+-+-+-+-+-+-+ -/
+ *
+ * PID: The relative Picture ID referred to by this frame.
+ * RS and RQ: The spatial and quality layer IDs.
+ * X: 1 if this layer index has an extended relative Picture ID.
+ */
+ if (has_ref_idc) {
+ while (ref_fields) {
+ if (len < 1) {
+ av_log(ctx, AV_LOG_ERROR, "Too short RTP/VP9 packet\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ has_ref_field_ext_pic_id = buf[0] & 0x10;
+
+ /* pass ref. field */
+ if (has_ref_field_ext_pic_id) {
+ if (len < 2) {
+ av_log(ctx, AV_LOG_ERROR, "Too short RTP/VP9 packet\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ /* ignore ref. data */
+
+ buf += 2;
+ len -= 2;
+ } else {
+
+ /* ignore ref. data */
+
+ buf++;
+ len--;
+ }
+ ref_fields--;
+ }
+ }
+
+ /*
+ * decode the scalability structure (SS)
+ *
+ * 0 1 2 3 4 5 6 7
+ * +-+-+-+-+-+-+-+-+
+ * V: | PATTERN LENGTH|
+ * +-+-+-+-+-+-+-+-+ -\
+ * | T | S | Q | R | (OPTIONAL) .
+ * +-+-+-+-+-+-+-+-+ -\ .
+ * | PID |X| RS| RQ| (OPTIONAL) . . - PAT. LEN. times
+ * +-+-+-+-+-+-+-+-+ . - R times .
+ * X: | EXTENDED PID | (OPTIONAL) . .
+ * +-+-+-+-+-+-+-+-+ -/ -/
+ *
+ * PID: The relative Picture ID referred to by this frame.
+ * RS and RQ: The spatial and quality layer IDs.
+ * X: 1 if this layer index has an extended relative Picture ID.
+ */
+ if (has_ss_data) {
+ avpriv_report_missing_feature(ctx, "VP9 scalability structure data\n");
+ return AVERROR_PATCHWELCOME;
+ }
+
+ /*
+ * decode the scalability update structure (SU)
+ *
+ * spec. is tbd
+ */
+ if (has_su_data) {
+ avpriv_report_missing_feature(ctx, "VP9 scalability update structure
data\n");
+ return AVERROR_PATCHWELCOME;
+ }
+
should be AVERROR(ENOSYS), report_missing_feature already prints a
similar message.
Okay.
I will send an update later today.
Best regards,
Thomas.
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