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-rw-r--r--v4l2-mfc-example/parser.c349
1 files changed, 349 insertions, 0 deletions
diff --git a/v4l2-mfc-example/parser.c b/v4l2-mfc-example/parser.c
new file mode 100644
index 0000000..6691dd1
--- /dev/null
+++ b/v4l2-mfc-example/parser.c
@@ -0,0 +1,349 @@
+/*
+ * V4L2 Codec decoding example application
+ * Kamil Debski <k.debski@samsung.com>
+ *
+ * Really simple stream parser file
+ *
+ * Copyright 2012 Samsung Electronics Co., Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include "common.h"
+#include "parser.h"
+#include <string.h>
+
+int parse_stream_init(struct mfc_parser_context *ctx)
+{
+ if (!ctx) {
+ err("ctx is NULL");
+ return -1;
+ }
+ memzero(*ctx);
+ return 0;
+}
+
+int parse_mpeg4_stream(
+ struct mfc_parser_context *ctx,
+ char* in, int in_size, char* out, int out_size,
+ int *consumed, int *frame_size, char get_head)
+{
+ char *in_orig;
+ char tmp;
+ char frame_finished;
+ int frame_length;
+
+ in_orig = in;
+
+ *consumed = 0;
+
+ frame_finished = 0;
+
+ while (in_size-- > 0) {
+ switch (ctx->state) {
+ case MPEG4_PARSER_NO_CODE:
+ if (*in == 0x0) {
+ ctx->state = MPEG4_PARSER_CODE_0x1;
+ ctx->tmp_code_start = *consumed;
+ }
+ break;
+ case MPEG4_PARSER_CODE_0x1:
+ if (*in == 0x0)
+ ctx->state = MPEG4_PARSER_CODE_0x2;
+ else
+ ctx->state = MPEG4_PARSER_NO_CODE;
+ break;
+ case MPEG4_PARSER_CODE_0x2:
+ if (*in == 0x1) {
+ ctx->state = MPEG4_PARSER_CODE_1x1;
+ } else if ((*in & 0xFC) == 0x80) {
+ // Short header
+ ctx->state = MPEG4_PARSER_NO_CODE;
+ ctx->last_tag = MPEG4_TAG_HEAD;
+ ctx->main_count++;
+ } else {
+ ctx->state = MPEG4_PARSER_NO_CODE;
+ }
+ break;
+ case MPEG4_PARSER_CODE_1x1:
+ tmp = *in & 0xF0;
+ if (tmp == 0x00 || tmp == 0x01 || tmp == 0x20 ||
+ *in == 0xb0 || *in == 0xb2 || *in == 0xb3 ||
+ *in == 0xb5) {
+ ctx->state = MPEG4_PARSER_NO_CODE;
+ ctx->last_tag = MPEG4_TAG_HEAD;
+ ctx->headers_count++;
+ } else if (*in == 0xb6) {
+ ctx->state = MPEG4_PARSER_NO_CODE;
+ ctx->last_tag = MPEG4_TAG_VOP;
+ ctx->main_count++;
+ } else
+ ctx->state = MPEG4_PARSER_NO_CODE;
+ break;
+ }
+
+ if (get_head == 1 && ctx->headers_count > 1 && ctx->main_count == 1) {
+ ctx->code_end = ctx->tmp_code_start;
+ ctx->got_end = 1;
+ break;
+ }
+
+ if (ctx->got_start == 0 && ctx->headers_count == 1 && ctx->main_count == 0) {
+ ctx->code_start = ctx->tmp_code_start;
+ ctx->got_start = 1;
+ }
+
+ if (ctx->got_start == 0 && ctx->headers_count == 0 && ctx->main_count == 1) {
+ ctx->code_start = ctx->tmp_code_start;
+ ctx->got_start = 1;
+ ctx->seek_end = 1;
+ ctx->headers_count = 0;
+ ctx->main_count = 0;
+ }
+
+ if (ctx->seek_end == 0 && ctx->headers_count > 0 && ctx->main_count == 1) {
+ ctx->seek_end = 1;
+ ctx->headers_count = 0;
+ ctx->main_count = 0;
+ }
+
+ if (ctx->seek_end == 1 && (ctx->headers_count > 0 || ctx->main_count > 0)) {
+ ctx->code_end = ctx->tmp_code_start;
+ ctx->got_end = 1;
+ if (ctx->headers_count == 0)
+ ctx->seek_end = 1;
+ else
+ ctx->seek_end = 0;
+ break;
+ }
+
+ in++;
+ (*consumed)++;
+ }
+
+
+ *frame_size = 0;
+
+ if (ctx->got_end == 1) {
+ frame_length = ctx->code_end;
+ } else
+ frame_length = *consumed;
+
+
+ if (ctx->code_start >= 0) {
+ frame_length -= ctx->code_start;
+ in = in_orig + ctx->code_start;
+ } else {
+ memcpy(out, ctx->bytes, -ctx->code_start);
+ *frame_size += -ctx->code_start;
+ out += -ctx->code_start;
+ in_size -= -ctx->code_start;
+ in = in_orig;
+ }
+
+ if (ctx->got_start) {
+ if (out_size < frame_length) {
+ err("Output buffer too small for current frame");
+ return 0;
+ }
+
+ memcpy(out, in, frame_length);
+ *frame_size += frame_length;
+
+ if (ctx->got_end) {
+ ctx->code_start = ctx->code_end - *consumed;
+ ctx->got_start = 1;
+ ctx->got_end = 0;
+ frame_finished = 1;
+ if (ctx->last_tag == MPEG4_TAG_VOP) {
+ ctx->seek_end = 1;
+ ctx->main_count = 0;
+ ctx->headers_count = 0;
+ } else {
+ ctx->seek_end = 0;
+ ctx->main_count = 0;
+ ctx->headers_count = 1;
+ }
+ memcpy(ctx->bytes, in_orig + ctx->code_end, *consumed - ctx->code_end);
+ } else {
+ ctx->code_start = 0;
+ frame_finished = 0;
+ }
+ }
+
+ ctx->tmp_code_start -= *consumed;
+
+ return frame_finished;
+}
+
+int parse_h264_stream(
+ struct mfc_parser_context *ctx,
+ char* in, int in_size, char* out, int out_size,
+ int *consumed, int *frame_size, char get_head)
+{
+ char *in_orig;
+ char tmp;
+ char frame_finished;
+ int frame_length;
+
+ in_orig = in;
+
+ *consumed = 0;
+
+ frame_finished = 0;
+
+ while (in_size-- > 0) {
+ switch (ctx->state) {
+ case H264_PARSER_NO_CODE:
+ if (*in == 0x0) {
+ ctx->state = H264_PARSER_CODE_0x1;
+ ctx->tmp_code_start = *consumed;
+ }
+ break;
+ case H264_PARSER_CODE_0x1:
+ if (*in == 0x0)
+ ctx->state = H264_PARSER_CODE_0x2;
+ else
+ ctx->state = H264_PARSER_NO_CODE;
+ break;
+ case H264_PARSER_CODE_0x2:
+ if (*in == 0x1) {
+ ctx->state = H264_PARSER_CODE_1x1;
+ } else if (*in == 0x0) {
+ ctx->state = H264_PARSER_CODE_0x3;
+ } else {
+ ctx->state = H264_PARSER_NO_CODE;
+ }
+ break;
+ case H264_PARSER_CODE_0x3:
+ if (*in == 0x1)
+ ctx->state = H264_PARSER_CODE_1x1;
+ else
+ ctx->state = H264_PARSER_NO_CODE;
+ break;
+ case H264_PARSER_CODE_1x1:
+ tmp = *in & 0x1F;
+
+ if (tmp == 1 || tmp == 5) {
+ ctx->state = H264_PARSER_CODE_SLICE;
+ } else if (tmp == 6 || tmp == 7 || tmp == 8) {
+ ctx->state = H264_PARSER_NO_CODE;
+ ctx->last_tag = H264_TAG_HEAD;
+ ctx->headers_count++;
+ }
+ else
+ ctx->state = H264_PARSER_NO_CODE;
+ break;
+ case H264_PARSER_CODE_SLICE:
+ if ((*in & 0x80) == 0x80) {
+ ctx->main_count++;
+ ctx->last_tag = H264_TAG_SLICE;
+ }
+ ctx->state = H264_PARSER_NO_CODE;
+ break;
+ }
+
+ if (get_head == 1 && ctx->headers_count > 1 && ctx->main_count == 1) {
+ ctx->code_end = ctx->tmp_code_start;
+ ctx->got_end = 1;
+ break;
+ }
+
+ if (ctx->got_start == 0 && ctx->headers_count == 1 && ctx->main_count == 0) {
+ ctx->code_start = ctx->tmp_code_start;
+ ctx->got_start = 1;
+ }
+
+ if (ctx->got_start == 0 && ctx->headers_count == 0 && ctx->main_count == 1) {
+ ctx->code_start = ctx->tmp_code_start;
+ ctx->got_start = 1;
+ ctx->seek_end = 1;
+ ctx->headers_count = 0;
+ ctx->main_count = 0;
+ }
+
+ if (ctx->seek_end == 0 && ctx->headers_count > 0 && ctx->main_count == 1) {
+ ctx->seek_end = 1;
+ ctx->headers_count = 0;
+ ctx->main_count = 0;
+ }
+
+ if (ctx->seek_end == 1 && (ctx->headers_count > 0 || ctx->main_count > 0)) {
+ ctx->code_end = ctx->tmp_code_start;
+ ctx->got_end = 1;
+ if (ctx->headers_count == 0)
+ ctx->seek_end = 1;
+ else
+ ctx->seek_end = 0;
+ break;
+ }
+
+ in++;
+ (*consumed)++;
+ }
+
+
+ *frame_size = 0;
+
+ if (ctx->got_end == 1) {
+ frame_length = ctx->code_end;
+ } else
+ frame_length = *consumed;
+
+
+ if (ctx->code_start >= 0) {
+ frame_length -= ctx->code_start;
+ in = in_orig + ctx->code_start;
+ } else {
+ memcpy(out, ctx->bytes, -ctx->code_start);
+ *frame_size += -ctx->code_start;
+ out += -ctx->code_start;
+ in_size -= -ctx->code_start;
+ in = in_orig;
+ }
+
+ if (ctx->got_start) {
+ if (out_size < frame_length) {
+ err("Output buffer too small for current frame");
+ return 0;
+ }
+ memcpy(out, in, frame_length);
+ *frame_size += frame_length;
+
+ if (ctx->got_end) {
+ ctx->code_start = ctx->code_end - *consumed;
+ ctx->got_start = 1;
+ ctx->got_end = 0;
+ frame_finished = 1;
+ if (ctx->last_tag == H264_TAG_SLICE) {
+ ctx->seek_end = 1;
+ ctx->main_count = 0;
+ ctx->headers_count = 0;
+ } else {
+ ctx->seek_end = 0;
+ ctx->main_count = 0;
+ ctx->headers_count = 1;
+ }
+ memcpy(ctx->bytes, in_orig + ctx->code_end, *consumed - ctx->code_end);
+ } else {
+ ctx->code_start = 0;
+ frame_finished = 0;
+ }
+ }
+
+ ctx->tmp_code_start -= *consumed;
+
+ return frame_finished;
+}
+
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