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avformat/evc: move NALU length and type parsing functions to a header 

Signed-off-by: James Almer <jamrial@gmail.com>
This commit is contained in:
James Almer 2023-06-20 10:31:24 -03:00
parent e5da2ec456
commit c7183a22db
3 changed files with 36 additions and 43 deletions
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5
libavformat/evc.c
View File

@ -23,7 +23,6 @@
#include "libavcodec/get_bits.h"
#include "libavcodec/golomb.h"
#include "libavcodec/evc.h"
#include "libavcodec/evc_parse.h"
#include "avformat.h"
#include "avio.h"
#include "evc.h"
@ -361,7 +360,7 @@ int ff_isom_write_evcc(AVIOContext *pb, const uint8_t *data,
evcc_init(&evcc);
while (bytes_to_read > EVC_NALU_LENGTH_PREFIX_SIZE) {
nalu_size = evc_read_nal_unit_length(data, EVC_NALU_LENGTH_PREFIX_SIZE, pb);
nalu_size = evc_read_nal_unit_length(data, EVC_NALU_LENGTH_PREFIX_SIZE);
if (nalu_size == 0) break;
data += EVC_NALU_LENGTH_PREFIX_SIZE;
@ -369,7 +368,7 @@ int ff_isom_write_evcc(AVIOContext *pb, const uint8_t *data,
if (bytes_to_read < nalu_size) break;
nalu_type = evc_get_nalu_type(data, bytes_to_read, pb);
nalu_type = evc_get_nalu_type(data, bytes_to_read);
if (nalu_type < EVC_NOIDR_NUT || nalu_type > EVC_UNSPEC_NUT62) {
ret = AVERROR_INVALIDDATA;
goto end;

30
libavformat/evc.h
View File

@ -24,9 +24,39 @@
#include <stdint.h>
#include "libavutil/rational.h"
#include "libavcodec/evc.h"
#include "avio.h"
static inline int evc_get_nalu_type(const uint8_t *bits, int bits_size)
{
int unit_type_plus1 = 0;
if (bits_size >= EVC_NALU_HEADER_SIZE) {
unsigned char *p = (unsigned char *)bits;
// forbidden_zero_bit
if ((p[0] & 0x80) != 0) // Cannot get bitstream information. Malformed bitstream.
return -1;
// nal_unit_type
unit_type_plus1 = (p[0] >> 1) & 0x3F;
}
return unit_type_plus1 - 1;
}
static inline uint32_t evc_read_nal_unit_length(const uint8_t *bits, int bits_size)
{
uint32_t nalu_len = 0;
if (bits_size >= EVC_NALU_LENGTH_PREFIX_SIZE) {
unsigned char *p = (unsigned char *)bits;
for (int i = 0; i < EVC_NALU_LENGTH_PREFIX_SIZE; i++)
nalu_len = (nalu_len << 8) | p[i];
}
return nalu_len;
}
/**
* Writes EVC sample metadata to the provided AVIOContext.

44
libavformat/evcdec.c
View File

@ -31,6 +31,7 @@
#include "rawdec.h"
#include "avformat.h"
#include "avio_internal.h"
#include "evc.h"
#include "internal.h"
@ -59,43 +60,6 @@ static const AVClass evc_demuxer_class = {
.version = LIBAVUTIL_VERSION_INT,
};
static int get_nalu_type(const uint8_t *bits, int bits_size)
{
int unit_type_plus1 = 0;
if (bits_size >= EVC_NALU_HEADER_SIZE) {
unsigned char *p = (unsigned char *)bits;
// forbidden_zero_bit
if ((p[0] & 0x80) != 0) // Cannot get bitstream information. Malformed bitstream.
return -1;
// nal_unit_type
unit_type_plus1 = (p[0] >> 1) & 0x3F;
}
return unit_type_plus1 - 1;
}
static uint32_t read_nal_unit_length(const uint8_t *bits, int bits_size)
{
uint32_t nalu_len = 0;
if (bits_size >= EVC_NALU_LENGTH_PREFIX_SIZE) {
int t = 0;
unsigned char *p = (unsigned char *)bits;
for (int i = 0; i < EVC_NALU_LENGTH_PREFIX_SIZE; i++)
t = (t << 8) | p[i];
nalu_len = t;
if (nalu_len == 0) // Invalid bitstream size
return 0;
}
return nalu_len;
}
static int annexb_probe(const AVProbeData *p)
{
int nalu_type;
@ -106,7 +70,7 @@ static int annexb_probe(const AVProbeData *p)
while (bytes_to_read > EVC_NALU_LENGTH_PREFIX_SIZE) {
nalu_size = read_nal_unit_length(bits, EVC_NALU_LENGTH_PREFIX_SIZE);
nalu_size = evc_read_nal_unit_length(bits, EVC_NALU_LENGTH_PREFIX_SIZE);
if (nalu_size == 0) break;
bits += EVC_NALU_LENGTH_PREFIX_SIZE;
@ -114,7 +78,7 @@ static int annexb_probe(const AVProbeData *p)
if(bytes_to_read < nalu_size) break;
nalu_type = get_nalu_type(bits, bytes_to_read);
nalu_type = evc_get_nalu_type(bits, bytes_to_read);
if (nalu_type == EVC_SPS_NUT)
got_sps++;
@ -199,7 +163,7 @@ static int evc_read_packet(AVFormatContext *s, AVPacket *pkt)
if (ret < 0)
return ret;
nalu_size = read_nal_unit_length((const uint8_t *)&buf, EVC_NALU_LENGTH_PREFIX_SIZE);
nalu_size = evc_read_nal_unit_length((const uint8_t *)&buf, EVC_NALU_LENGTH_PREFIX_SIZE);
if (!nalu_size || nalu_size > INT_MAX)
return AVERROR_INVALIDDATA;