cbs_h2645: Merge SEI message handling in common between codecs

1 files changed, 139 insertions, 0 deletions

diff --git a/libavcodec/cbs_sei.h b/libavcodec/cbs_sei.h
index 95beabf4d7..c7a7a95be0 100644
--- a/libavcodec/cbs_sei.h
+++ b/libavcodec/cbs_sei.h
@@ -21,8 +21,16 @@
 
 #include <stddef.h>
 #include <stdint.h>
+
 #include "libavutil/buffer.h"
 
+#include "cbs.h"
+#include "sei.h"
+
+
+typedef struct SEIRawFillerPayload {
+    uint32_t payload_size;
+} SEIRawFillerPayload;
 
 typedef struct SEIRawUserDataRegistered {
     uint8_t      itu_t_t35_country_code;
@@ -57,4 +65,135 @@ typedef struct SEIRawAlternativeTransferCharacteristics {
     uint8_t preferred_transfer_characteristics;
 } SEIRawAlternativeTransferCharacteristics;
 
+typedef struct SEIRawMessage {
+    uint32_t     payload_type;
+    uint32_t     payload_size;
+    void        *payload;
+    AVBufferRef *payload_ref;
+    uint8_t     *extension_data;
+    AVBufferRef *extension_data_ref;
+    size_t       extension_bit_length;
+} SEIRawMessage;
+
+typedef struct SEIRawMessageList {
+    SEIRawMessage *messages;
+    int         nb_messages;
+    int         nb_messages_allocated;
+} SEIRawMessageList;
+
+
+typedef struct SEIMessageState {
+    // The type of the payload being written.
+    uint32_t payload_type;
+    // When reading, contains the size of the payload to allow finding the
+    // end of variable-length fields (such as user_data_payload_byte[]).
+    // (When writing, the size will be derived from the total number of
+    // bytes actually written.)
+    uint32_t payload_size;
+    // When writing, indicates that payload extension data is present so
+    // all extended fields must be written.  May be updated by the writer
+    // to indicate that extended fields have been written, so the extension
+    // end bits must be written too.
+    uint8_t  extension_present;
+} SEIMessageState;
+
+struct GetBitContext;
+struct PutBitContext;
+
+typedef int (*SEIMessageReadFunction)(CodedBitstreamContext *ctx,
+                                      struct GetBitContext *rw,
+                                      void *current,
+                                      SEIMessageState *sei);
+
+typedef int (*SEIMessageWriteFunction)(CodedBitstreamContext *ctx,
+                                       struct PutBitContext *rw,
+                                       void *current,
+                                       SEIMessageState *sei);
+
+typedef struct SEIMessageTypeDescriptor {
+    // Payload type for the message.  (-1 in this field ends a list.)
+    int     type;
+    // Valid in a prefix SEI NAL unit (always for H.264).
+    uint8_t prefix;
+    // Valid in a suffix SEI NAL unit (never for H.264).
+    uint8_t suffix;
+    // Size of the decomposed structure.
+    size_t  size;
+    // Read bitstream into SEI message.
+    SEIMessageReadFunction  read;
+    // Write bitstream from SEI message.
+    SEIMessageWriteFunction write;
+} SEIMessageTypeDescriptor;
+
+// Macro for the read/write pair.  The clumsy cast is needed because the
+// current pointer is typed in all of the read/write functions but has to
+// be void here to fit all cases.
+#define SEI_MESSAGE_RW(codec, name) \
+    .read  = (SEIMessageReadFunction) cbs_ ## codec ## _read_  ## name, \
+    .write = (SEIMessageWriteFunction)cbs_ ## codec ## _write_ ## name
+
+// End-of-list sentinel element.
+#define SEI_MESSAGE_TYPE_END { .type = -1 }
+
+
+/**
+ * Find the type descriptor for the given payload type.
+ *
+ * Returns NULL if the payload type is not known.
+ */
+const SEIMessageTypeDescriptor *ff_cbs_sei_find_type(CodedBitstreamContext *ctx,
+                                                     int payload_type);
+
+/**
+ * Allocate a new payload for the given SEI message.
+ */
+int ff_cbs_sei_alloc_message_payload(SEIRawMessage *message,
+                                     const SEIMessageTypeDescriptor *desc);
+
+/**
+ * Allocate a new empty SEI message in a message list.
+ *
+ * The new message is in place nb_messages - 1.
+ */
+int ff_cbs_sei_list_add(SEIRawMessageList *list);
+
+/**
+ * Free all SEI messages in a message list.
+ */
+void ff_cbs_sei_free_message_list(SEIRawMessageList *list);
+
+/**
+ * Add an SEI message to an access unit.
+ *
+ * Will add to an existing SEI NAL unit, or create a new one for the
+ * message if there is no suitable existing one.
+ *
+ * Takes a new reference to payload_buf, if set.  If payload_buf is
+ * NULL then the new message will not be reference counted.
+ */
+int ff_cbs_sei_add_message(CodedBitstreamContext *ctx,
+                           CodedBitstreamFragment *au,
+                           int prefix,
+                           uint32_t     payload_type,
+                           void        *payload_data,
+                           AVBufferRef *payload_buf);
+
+/**
+ * Iterate over messages with the given payload type in an access unit.
+ *
+ * Set message to NULL in the first call.  Returns 0 while more messages
+ * are available, AVERROR(ENOENT) when all messages have been found.
+ */
+int ff_cbs_sei_find_message(CodedBitstreamContext *ctx,
+                            CodedBitstreamFragment *au,
+                            uint32_t payload_type,
+                            SEIRawMessage **message);
+
+/**
+ * Delete all messages with the given payload type from an access unit.
+ */
+void ff_cbs_sei_delete_message_type(CodedBitstreamContext *ctx,
+                                    CodedBitstreamFragment *au,
+                                    uint32_t payload_type);
+
 #endif /* AVCODEC_CBS_SEI_H */