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Code Issues Releases Activity

libavcodec/jpeg2000_parser: Simplify, fix reset_context()

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This commit is contained in:
Tomas Härdin
2022-05-20 11:44:06 +02:00
parent 1ee994e168
commit 5cfc1b0595
1 changed files with 10 additions and 13 deletions
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23
libavcodec/jpeg2000_parser.c
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@@ -51,7 +51,7 @@ static inline void reset_context(JPEG2000ParserContext *m)
ParseContext *pc = &m->pc; ParseContext *pc = &m->pc;
pc->frame_start_found= 0; pc->frame_start_found= 0;
pc->state = 0; pc->state64 = 0;
m->bytes_read = 0; m->bytes_read = 0;
m->ft = 0; m->ft = 0;
m->skipped_codestream = 0; m->skipped_codestream = 0;
@@ -82,16 +82,14 @@ static int find_frame_end(JPEG2000ParserContext *m, const uint8_t *buf, int buf_
{ {
ParseContext *pc= &m->pc; ParseContext *pc= &m->pc;
int i; int i;
uint32_t state, next_state; uint32_t next_state;
uint64_t state64; uint64_t state64 = pc->state64;
state= pc->state;
state64 = pc->state64;
if (buf_size == 0) { if (buf_size == 0) {
return 0; return 0;
} }
for (i = 0; i < buf_size; i++) { for (i = 0; i < buf_size; i++) {
state = state << 8 | buf[i];
state64 = state64 << 8 | buf[i]; state64 = state64 << 8 | buf[i];
m->bytes_read++; m->bytes_read++;
if (m->skip_bytes) { if (m->skip_bytes) {
@@ -132,9 +130,9 @@ static int find_frame_end(JPEG2000ParserContext *m, const uint8_t *buf, int buf_
} }
m->fheader_read--; m->fheader_read--;
} }
if (state == 0x0000000C && m->bytes_read >= 3) { // Indicates start of JP2 file. Check signature next. if ((state64 & 0xFFFFFFFF) == 0x0000000C && m->bytes_read >= 3) { // Indicates start of JP2 file. Check signature next.
m->fheader_read = 8; m->fheader_read = 8;
} else if ((state & 0xFFFF) == 0xFF4F) { } else if ((state64 & 0xFFFF) == 0xFF4F) {
m->in_codestream = 1; m->in_codestream = 1;
if (!pc->frame_start_found) { if (!pc->frame_start_found) {
pc->frame_start_found = 1; pc->frame_start_found = 1;
@@ -143,7 +141,7 @@ static int find_frame_end(JPEG2000ParserContext *m, const uint8_t *buf, int buf_
reset_context(m); reset_context(m);
return i - 1; return i - 1;
} }
} else if ((state & 0xFFFF) == 0xFFD9) { } else if ((state64 & 0xFFFF) == 0xFFD9) {
if (pc->frame_start_found && m->ft == jp2_file) { if (pc->frame_start_found && m->ft == jp2_file) {
m->skipped_codestream = 1; m->skipped_codestream = 1;
} else if (pc->frame_start_found && m->ft == j2k_cstream) { } else if (pc->frame_start_found && m->ft == j2k_cstream) {
@@ -151,11 +149,11 @@ static int find_frame_end(JPEG2000ParserContext *m, const uint8_t *buf, int buf_
return i + 1; // End of frame detected, return frame size. return i + 1; // End of frame detected, return frame size.
} }
m->in_codestream = 0; m->in_codestream = 0;
} else if (m->in_codestream && (state & 0xFFFF) == 0xFF90) { // Are we in tile part header? } else if (m->in_codestream && (state64 & 0xFFFF) == 0xFF90) { // Are we in tile part header?
m->read_tp = 8; m->read_tp = 8;
} else if (pc->frame_start_found && info_marker((state & 0xFFFF0000)>>16) && m->in_codestream && (state & 0xFFFF)) { } else if (pc->frame_start_found && info_marker((state64 & 0xFFFF0000)>>16) && m->in_codestream && (state64 & 0xFFFF)) {
// Calculate number of bytes to skip to get to end of the next marker. // Calculate number of bytes to skip to get to end of the next marker.
m->skip_bytes = (state & 0xFFFF)-1; m->skip_bytes = (state64 & 0xFFFF)-1;
// If the next marker is an info marker, skip to the end of of the marker length. // If the next marker is an info marker, skip to the end of of the marker length.
if (i + m->skip_bytes + 1 < buf_size) { if (i + m->skip_bytes + 1 < buf_size) {
@@ -168,7 +166,6 @@ static int find_frame_end(JPEG2000ParserContext *m, const uint8_t *buf, int buf_
} }
} }
pc->state = state;
pc->state64 = state64; pc->state64 = state64;
return END_NOT_FOUND; return END_NOT_FOUND;
} }