res_format_attr_h263: Generate valid SDP fmtp for H.263+.

Fixed:
* RFC 4629 does not allow the value "0" for MPI, K, and N.
* Allow value "0" for PAR.
* BPP is printed only when specified because "0" has a meaning.

New:
* Added CPCF and MaxBR.
* Some implementations provide CIF without MPI: a=fmtp:xx CIF;F=1
  Although a violation of RFC 3555 section 3, we can support that.

Changed:
* Resorts the CIFs from large to small which partly fixes ASTERISK~29267.

Change-Id: I95a650c715007b8dde11a77cb37d9c6c123a441e

diff --git a/res/res_format_attr_h263.c b/res/res_format_attr_h263.c
index b49f1d681ce52b6e532d40e2ae81a40a63c4ba8f..5246725ede15a4185beb360483292c04a5aa9e54 100644 (file)
--- a/res/res_format_attr_h263.c
+++ b/res/res_format_attr_h263.c
@@ -36,6 +36,9 @@
 #include "asterisk/module.h"
 #include "asterisk/format.h"
 
+/*! \brief Value that indicates an attribute is actually unset */
+#define H263_ATTR_KEY_UNSET UINT8_MAX
+
 struct h263_attr {
        unsigned int SQCIF;       /*!< Minimum picture interval for SQCIF resolution */
        unsigned int QCIF;        /*!< Minimum picture interval for QCIF resolution */
@@ -46,6 +49,14 @@ struct h263_attr {
        unsigned int CUSTOM_XMAX; /*!< Custom resolution (Xmax) */
        unsigned int CUSTOM_YMAX; /*!< Custom resolution (Ymax) */
        unsigned int CUSTOM_MPI;  /*!< Custom resolution (MPI) */
+       unsigned int CPCF;        /*!< Custom Picture Clock Frequency */
+       unsigned int CPCF_2;
+       unsigned int CPCF_3;
+       unsigned int CPCF_4;
+       unsigned int CPCF_5;
+       unsigned int CPCF_6;
+       unsigned int CPCF_7;
+       unsigned int CPCF_MPI;
        unsigned int F;           /*!< F annex support */
        unsigned int I;           /*!< I annex support */
        unsigned int J;           /*!< J annex support */
@@ -60,6 +71,7 @@ struct h263_attr {
        unsigned int PAR_HEIGHT;  /*!< Pixel aspect ratio (height) */
        unsigned int BPP;         /*!< Bits per picture maximum */
        unsigned int HRD;         /*!< Hypothetical reference decoder status */
+       unsigned int MaxBR;       /*!< Vendor Specific: CounterPath Bria (Solo) */
 };
 
 static void h263_destroy(struct ast_format *format)
@@ -123,6 +135,14 @@ static struct ast_format *h263_getjoint(const struct ast_format *format1, const
        DETERMINE_JOINT(attr, attr1, attr2, CUSTOM_XMAX);
        DETERMINE_JOINT(attr, attr1, attr2, CUSTOM_YMAX);
        DETERMINE_JOINT(attr, attr1, attr2, CUSTOM_MPI);
+       DETERMINE_JOINT(attr, attr1, attr2, CPCF);
+       DETERMINE_JOINT(attr, attr1, attr2, CPCF_2);
+       DETERMINE_JOINT(attr, attr1, attr2, CPCF_3);
+       DETERMINE_JOINT(attr, attr1, attr2, CPCF_4);
+       DETERMINE_JOINT(attr, attr1, attr2, CPCF_5);
+       DETERMINE_JOINT(attr, attr1, attr2, CPCF_6);
+       DETERMINE_JOINT(attr, attr1, attr2, CPCF_7);
+       DETERMINE_JOINT(attr, attr1, attr2, CPCF_MPI);
        DETERMINE_JOINT(attr, attr1, attr2, F);
        DETERMINE_JOINT(attr, attr1, attr2, I);
        DETERMINE_JOINT(attr, attr1, attr2, J);
@@ -137,6 +157,7 @@ static struct ast_format *h263_getjoint(const struct ast_format *format1, const
        DETERMINE_JOINT(attr, attr1, attr2, PAR_HEIGHT);
        DETERMINE_JOINT(attr, attr1, attr2, BPP);
        DETERMINE_JOINT(attr, attr1, attr2, HRD);
+       DETERMINE_JOINT(attr, attr1, attr2, MaxBR);
 
        return cloned;
 }
@@ -153,27 +174,54 @@ static struct ast_format *h263_parse_sdp_fmtp(const struct ast_format *format, c
        }
        attr = ast_format_get_attribute_data(cloned);
 
+       attr->BPP = H263_ATTR_KEY_UNSET;
+       attr->MaxBR = H263_ATTR_KEY_UNSET;
+       attr->PAR_WIDTH = H263_ATTR_KEY_UNSET;
+       attr->PAR_HEIGHT = H263_ATTR_KEY_UNSET;
+
        while ((attrib = strsep(&attribs, ";"))) {
-               unsigned int val, val2 = 0, val3 = 0, val4 = 0;
+               unsigned int val, val2 = 0, val3 = 0, val4 = 0, val5 = 0, val6 = 0, val7 = 0, val8 = 0;
 
                attrib = ast_strip(attrib);
 
                if (sscanf(attrib, "SQCIF=%30u", &val) == 1) {
                        attr->SQCIF = val;
+               } else if (strcmp(attrib, "SQCIF") == 0) {
+                       attr->SQCIF = 1;
                } else if (sscanf(attrib, "QCIF=%30u", &val) == 1) {
                        attr->QCIF = val;
+               } else if (strcmp(attrib, "QCIF") == 0) {
+                       attr->QCIF = 1;
                } else if (sscanf(attrib, "CIF=%30u", &val) == 1) {
                        attr->CIF = val;
+               } else if (strcmp(attrib, "CIF") == 0) {
+                       attr->CIF = 1;
                } else if (sscanf(attrib, "CIF4=%30u", &val) == 1) {
                        attr->CIF4 = val;
+               } else if (strcmp(attrib, "CIF4") == 0) {
+                       attr->CIF4 = 1;
                } else if (sscanf(attrib, "CIF16=%30u", &val) == 1) {
                        attr->CIF16 = val;
+               } else if (strcmp(attrib, "CIF16") == 0) {
+                       attr->CIF16 = 1;
                } else if (sscanf(attrib, "VGA=%30u", &val) == 1) {
                        attr->VGA = val;
+               } else if (strcmp(attrib, "VGA") == 0) {
+                       attr->VGA = 1;
                } else if (sscanf(attrib, "CUSTOM=%30u,%30u,%30u", &val, &val2, &val3) == 3) {
                        attr->CUSTOM_XMAX = val;
                        attr->CUSTOM_YMAX = val2;
                        attr->CUSTOM_MPI = val3;
+               } else if (sscanf(attrib, "CPCF=%30u,%30u,%30u,%30u,%30u,%30u,%30u,%30u",
+                               &val, &val2, &val3, &val4, &val5, &val6, &val7, &val8) == 8) {
+                       attr->CPCF = val;
+                       attr->CPCF_2 = val2;
+                       attr->CPCF_3 = val3;
+                       attr->CPCF_4 = val4;
+                       attr->CPCF_5 = val5;
+                       attr->CPCF_6 = val6;
+                       attr->CPCF_7 = val7;
+                       attr->CPCF_MPI = val8;
                } else if (sscanf(attrib, "F=%30u", &val) == 1) {
                        attr->F = val;
                } else if (sscanf(attrib, "I=%30u", &val) == 1) {
@@ -198,34 +246,85 @@ static struct ast_format *h263_parse_sdp_fmtp(const struct ast_format *format, c
                        attr->P_SUB2 = val2;
                        attr->P_SUB3 = val3;
                        attr->P_SUB4 = val4;
+               } else if (sscanf(attrib, "MAXBR=%30u", &val) == 1) {
+                       attr->MaxBR = val;
                }
        }
 
        return cloned;
 }
 
+#define APPEND_IF_NOT_H263_UNSET(field, str, name) do {                \
+       if (field != H263_ATTR_KEY_UNSET) {     \
+               if (added) {    \
+                       ast_str_append(str, 0, ";");    \
+               } else if (0 < ast_str_append(str, 0, "a=fmtp:%u ", payload)) { \
+                       added = 1;      \
+               }       \
+               ast_str_append(str, 0, "%s=%u", name, field);   \
+       }       \
+} while (0)
+
+#define APPEND_IF_NONZERO(field, str, name) do {               \
+       if (field) {    \
+               if (added) {    \
+                       ast_str_append(str, 0, ";");    \
+               } else if (0 < ast_str_append(str, 0, "a=fmtp:%u ", payload)) { \
+                       added = 1;      \
+               }       \
+               ast_str_append(str, 0, "%s=%u", name, field);   \
+       }       \
+} while (0)
+
 static void h263_generate_sdp_fmtp(const struct ast_format *format, unsigned int payload, struct ast_str **str)
 {
        struct h263_attr *attr = ast_format_get_attribute_data(format);
+       int added = 0;
 
        if (!attr) {
                return;
        }
 
-       ast_str_append(str, 0, "a=fmtp:%u SQCIF=%u;QCIF=%u;CIF=%u;CIF4=%u;CIF16=%u;VGA=%u;F=%u;I=%u;J=%u;T=%u;K=%u;N=%u;BPP=%u;HRD=%u",
-               payload, attr->SQCIF, attr->QCIF, attr->CIF, attr->CIF4, attr->CIF16, attr->VGA, attr->F, attr->I, attr->J,
-               attr->T, attr->K, attr->N, attr->BPP, attr->HRD);
+       if (attr->CPCF) {
+               if (added) {
+                       ast_str_append(str, 0, ";");
+               } else if (0 < ast_str_append(str, 0, "a=fmtp:%u ", payload)) {
+                       added = 1;
+               }
+               ast_str_append(str, 0, "CPCF=%u,%u,%u,%u,%u,%u,%u,%u", attr->CPCF, attr->CPCF_2, attr->CPCF_3,
+                       attr->CPCF_4, attr->CPCF_5, attr->CPCF_6, attr->CPCF_7, attr->CPCF_MPI);
+       }
+
+       APPEND_IF_NONZERO(attr->CIF16, str, "CIF16");
+       APPEND_IF_NONZERO(attr->CIF4,  str, "CIF4");
+       APPEND_IF_NONZERO(attr->VGA,   str, "VGA");
+       APPEND_IF_NONZERO(attr->CIF,   str, "CIF");
+       APPEND_IF_NONZERO(attr->QCIF,  str, "QCIF");
+       APPEND_IF_NONZERO(attr->SQCIF, str, "SQCIF");
 
        if (attr->CUSTOM_XMAX && attr->CUSTOM_YMAX && attr->CUSTOM_MPI) {
-               ast_str_append(str, 0, ";CUSTOM=%u,%u,%u", attr->CUSTOM_XMAX, attr->CUSTOM_YMAX, attr->CUSTOM_MPI);
+               if (added) {
+                       ast_str_append(str, 0, ";");
+               } else if (0 < ast_str_append(str, 0, "a=fmtp:%u ", payload)) {
+                       added = 1;
+               }
+               ast_str_append(str, 0, "CUSTOM=%u,%u,%u", attr->CUSTOM_XMAX, attr->CUSTOM_YMAX, attr->CUSTOM_MPI);
        }
 
-       if (attr->PAR_WIDTH && attr->PAR_HEIGHT) {
-               ast_str_append(str, 0, ";PAR=%u:%u", attr->PAR_WIDTH, attr->PAR_HEIGHT);
-       }
+       APPEND_IF_NONZERO(attr->F, str, "F");
+       APPEND_IF_NONZERO(attr->I, str, "I");
+       APPEND_IF_NONZERO(attr->J, str, "J");
+       APPEND_IF_NONZERO(attr->T, str, "T");
+       APPEND_IF_NONZERO(attr->K, str, "K");
+       APPEND_IF_NONZERO(attr->N, str, "N");
 
        if (attr->P_SUB1) {
-               ast_str_append(str, 0, ";P=%u", attr->P_SUB1);
+               if (added) {
+                       ast_str_append(str, 0, ";");
+               } else if (0 < ast_str_append(str, 0, "a=fmtp:%u ", payload)) {
+                       added = 1;
+               }
+               ast_str_append(str, 0, "P=%u", attr->P_SUB1);
                if (attr->P_SUB2) {
                        ast_str_append(str, 0, ",%u", attr->P_SUB2);
                }
@@ -237,6 +336,21 @@ static void h263_generate_sdp_fmtp(const struct ast_format *format, unsigned int
                }
        }
 
+       if (attr->PAR_WIDTH != H263_ATTR_KEY_UNSET && attr->PAR_HEIGHT != H263_ATTR_KEY_UNSET) {
+               if (added) {
+                       ast_str_append(str, 0, ";");
+               } else if (0 < ast_str_append(str, 0, "a=fmtp:%u ", payload)) {
+                       added = 1;      \
+               }
+               ast_str_append(str, 0, "PAR=%u:%u", attr->PAR_WIDTH, attr->PAR_HEIGHT);
+       }
+
+       APPEND_IF_NOT_H263_UNSET(attr->BPP, str, "BPP");
+
+       APPEND_IF_NONZERO(attr->HRD, str, "HRD");
+
+       APPEND_IF_NOT_H263_UNSET(attr->MaxBR, str, "MaxBR");
+
        ast_str_append(str, 0, "\r\n");
 
        return;