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libobs: Implement obs_parse_hevc_packet

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This commit is contained in:
jpark37 2022-07-31 17:09:16 -07:00
parent 55f35d1d89
commit 5361d936ce
2 changed files with 63 additions and 1 deletions
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60
libobs/obs-hevc.c
View File

@ -17,8 +17,9 @@
#include "obs-hevc.h"
#include "obs.h"
#include "obs-nal.h"
#include "util/darray.h"
#include "util/array-serializer.h"
enum {
OBS_HEVC_NAL_TRAIL_N = 0,
@ -89,6 +90,63 @@ bool obs_hevc_keyframe(const uint8_t *data, size_t size)
return false;
}
static void serialize_hevc_data(struct serializer *s, const uint8_t *data,
size_t size, bool *is_keyframe, int *priority)
{
const uint8_t *const end = data + size;
const uint8_t *nal_start = obs_nal_find_startcode(data, end);
while (true) {
while (nal_start < end && !*(nal_start++))
;
if (nal_start == end)
break;
// HEVC contains NAL unit specifier at [6..1] bits of
// the byte next to the startcode 0x000001
const int type = (nal_start[0] & 0x7F) >> 1;
// Mark IDR slices as key-frames and set them to highest
// priority if needed. Assume other slices are non-key
// frames and set their priority as high
if (type >= OBS_HEVC_NAL_BLA_W_LP &&
type <= OBS_HEVC_NAL_RSV_IRAP_VCL23) {
*is_keyframe = 1;
*priority = OBS_NAL_PRIORITY_HIGHEST;
} else if (type >= OBS_HEVC_NAL_TRAIL_N &&
type <= OBS_HEVC_NAL_RASL_R) {
if (*priority < OBS_NAL_PRIORITY_HIGH)
*priority = OBS_NAL_PRIORITY_HIGH;
}
const uint8_t *const nal_end =
obs_nal_find_startcode(nal_start, end);
const size_t size = nal_end - nal_start;
s_wb32(s, (uint32_t)size);
s_write(s, nal_start, size);
nal_start = nal_end;
}
}
void obs_parse_hevc_packet(struct encoder_packet *hevc_packet,
const struct encoder_packet *src)
{
struct array_output_data output;
struct serializer s;
long ref = 1;
array_output_serializer_init(&s, &output);
*hevc_packet = *src;
serialize(&s, &ref, sizeof(ref));
serialize_hevc_data(&s, src->data, src->size, &hevc_packet->keyframe,
&hevc_packet->priority);
hevc_packet->data = output.bytes.array + sizeof(ref);
hevc_packet->size = output.bytes.num - sizeof(ref);
hevc_packet->drop_priority = hevc_packet->priority;
}
void obs_extract_hevc_headers(const uint8_t *packet, size_t size,
uint8_t **new_packet_data,
size_t *new_packet_size, uint8_t **header_data,

4
libobs/obs-hevc.h
View File

@ -23,7 +23,11 @@
extern "C" {
#endif
struct encoder_packet;
EXPORT bool obs_hevc_keyframe(const uint8_t *data, size_t size);
EXPORT void obs_parse_hevc_packet(struct encoder_packet *hevc_packet,
const struct encoder_packet *src);
EXPORT void obs_extract_hevc_headers(const uint8_t *packet, size_t size,
uint8_t **new_packet_data,
size_t *new_packet_size,