[FFmpeg-devel] [PATCH v3 1/2] lavc: add prores bitstream parser

[hung kuishing]

Signed-off-by: clarkh <hungkuishing at outlook.com>
---
 libavcodec/Makefile        |   1 +
 libavcodec/parsers.c       |   1 +
 libavcodec/prores_parser.c | 107 +++++++++++++++++++++++++++++++++++++
 3 files changed, 109 insertions(+)
 create mode 100644 libavcodec/prores_parser.c

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 1b0226c089..21cd28c9ac 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -1198,6 +1198,7 @@ OBJS-$(CONFIG_OPUS_PARSER)             += opus_parser.o opus_parse.o \
                                           vorbis_data.o
 OBJS-$(CONFIG_PNG_PARSER)              += png_parser.o
 OBJS-$(CONFIG_PNM_PARSER)              += pnm_parser.o pnm.o
+OBJS-$(CONFIG_PRORES_PARSER)           += prores_parser.o
 OBJS-$(CONFIG_QOI_PARSER)              += qoi_parser.o
 OBJS-$(CONFIG_RV30_PARSER)             += rv34_parser.o
 OBJS-$(CONFIG_RV40_PARSER)             += rv34_parser.o
diff --git a/libavcodec/parsers.c b/libavcodec/parsers.c
index 285f81a901..131867686a 100644
--- a/libavcodec/parsers.c
+++ b/libavcodec/parsers.c
@@ -64,6 +64,7 @@ extern const AVCodecParser ff_mpegvideo_parser;
 extern const AVCodecParser ff_opus_parser;
 extern const AVCodecParser ff_png_parser;
 extern const AVCodecParser ff_pnm_parser;
+extern const AVCodecParser ff_prores_parser;
 extern const AVCodecParser ff_qoi_parser;
 extern const AVCodecParser ff_rv30_parser;
 extern const AVCodecParser ff_rv40_parser;
diff --git a/libavcodec/prores_parser.c b/libavcodec/prores_parser.c
new file mode 100644
index 0000000000..1299c7b642
--- /dev/null
+++ b/libavcodec/prores_parser.c
@@ -0,0 +1,107 @@
+/*
+ * ProRes bitstream parser
+ * Copyright (c) 2023 clarkh <hungkuishing at outlook.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "parser.h"
+#include "libavutil/intreadwrite.h"
+#include "libavcodec/proresdata.h"
+
+typedef struct {
+    ParseContext pc;
+    int remaining;
+    int overwrite;
+} ProResParserContext;
+
+static int prores_find_frame_end(ProResParserContext *pctx, const uint8_t *buf, int buf_size)
+{
+    ParseContext *pc = &pctx->pc;
+    uint64_t state64 = pc->state64;
+    int pic_found = pc->frame_start_found;
+    int i = 0;
+
+    if (!pic_found) {
+        for (i = 0; i < buf_size; i++) {
+            state64 = (state64 << 8) | buf[i];
+            if ((state64 & 0xFFFFFFFF) == FRAME_ID) {
+                i++;
+                pic_found = 1;
+                pctx->remaining = state64 >> 32;
+                pctx->remaining -= pctx->overwrite;
+                break;
+            }
+        }
+    }
+
+    if (pic_found) {
+        if (!buf_size)
+            return END_NOT_FOUND;
+
+        if (pctx->remaining > buf_size) {
+            pctx->remaining -= buf_size;
+        } else {
+            int remaining = pctx->remaining;
+
+            pc->frame_start_found = 0;
+            pc->state64 = -1;
+            pctx->remaining = 0;
+            pctx->overwrite = 0;
+            return remaining;
+        }
+    } else {
+        pctx->overwrite += buf_size;
+    }
+
+    pc->frame_start_found = pic_found;
+    pc->state64 = state64;
+
+    return END_NOT_FOUND;
+}
+
+static int prores_parse(AVCodecParserContext *s, AVCodecContext *avctx,
+                      const uint8_t **poutbuf, int *poutbuf_size,
+                      const uint8_t *buf, int buf_size)
+{
+    ProResParserContext *pctx = s->priv_data;
+    ParseContext *pc = &pctx->pc;
+    int next;
+
+    if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
+        next = buf_size;
+    } else {
+        next = prores_find_frame_end(pctx, buf, buf_size);
+        if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
+            *poutbuf = NULL;
+            *poutbuf_size = 0;
+            return buf_size;
+        }
+    }
+
+    *poutbuf = buf;
+    *poutbuf_size = buf_size;
+
+    return next;
+}
+
+const AVCodecParser ff_prores_parser = {
+    .codec_ids      = { AV_CODEC_ID_PRORES },
+    .priv_data_size = sizeof(ProResParserContext),
+    .parser_parse   = prores_parse,
+    .parser_close   = ff_parse_close
+};
-- 
2.34.1