[FFmpeg-devel] [PATCH v9 3/6] libavcodec/dnxuc_parser: DNxUncompressed essence parser
Martin Schitter
ms+git at mur.at
Mon Sep 23 12:16:44 EEST 2024
---
libavcodec/Makefile | 1 +
libavcodec/dnxuc_parser.c | 124 ++++++++++++++++++++++++++++++++++++++
libavcodec/parsers.c | 1 +
3 files changed, 126 insertions(+)
create mode 100644 libavcodec/dnxuc_parser.c
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 936fc34..76366b3 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -1191,6 +1191,7 @@ OBJS-$(CONFIG_DCA_PARSER) += dca_parser.o dca_exss.o dca.o \
dca_sample_rate_tab.o
OBJS-$(CONFIG_DIRAC_PARSER) += dirac_parser.o
OBJS-$(CONFIG_DNXHD_PARSER) += dnxhd_parser.o dnxhddata.o
+OBJS-$(CONFIG_DNXUC_PARSER) += dnxuc_parser.o
OBJS-$(CONFIG_DOLBY_E_PARSER) += dolby_e_parser.o dolby_e_parse.o
OBJS-$(CONFIG_DPX_PARSER) += dpx_parser.o
OBJS-$(CONFIG_DVAUDIO_PARSER) += dvaudio_parser.o
diff --git a/libavcodec/dnxuc_parser.c b/libavcodec/dnxuc_parser.c
new file mode 100644
index 0000000..55d5763
--- /dev/null
+++ b/libavcodec/dnxuc_parser.c
@@ -0,0 +1,124 @@
+/*
+ * Avid DNxUncomressed / SMPTE RDD 50 parser
+ * Copyright (c) 2024 Martin Schitter
+ *
+ * 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
+ */
+
+/*
+ This parser for DNxUncompressed video data is mostly based on
+ reverse engineering of output generated by DaVinci Resolve 19
+ but was later also checked against the SMPTE RDD 50 specification.
+
+ Limitations: Multiple image planes are not supported.
+*/
+
+#include "avcodec.h"
+#include "libavutil/intreadwrite.h"
+
+typedef struct DNxUcParseContext {
+ uint32_t fourcc_tag;
+ uint32_t width;
+ uint32_t height;
+ uint32_t nr_bytes;
+} DNxUcParseContext;
+
+/*
+DNxUncompressed frame data comes wrapped in nested boxes of metadata
+(box structure: len + fourcc marker + data):
+
+[0-4] len of outer essence unit box (typically 37 bytes of header + frame data)
+[4-7] fourcc 'pack'
+
+[8-11] len of "signal info box" (always 21)
+[12-15] fourcc 'sinf'
+[16-19] frame width / line packing size
+[20-23] frame hight / nr of lines
+[24-27] fourcc pixel format indicator
+[28] frame_layout (0: progressive, 1: interlaced)
+
+[29-32] len of "signal data box" (nr of frame data bytes + 8)
+[33-36] fourcc 'sdat'
+[37-..] frame data
+
+A sequence of 'signal info'+'signal data' box pairs wrapped in
+'icmp'(=image component) boxes can be utilized to compose more
+complex multi plane images.
+This feature is only partially supported in the present implementation.
+We never pick more than the first pair of info and image data enclosed
+in this way.
+*/
+
+static int dnxuc_parse(AVCodecParserContext *s,
+ AVCodecContext *avctx,
+ const uint8_t **poutbuf, int *poutbuf_size,
+ const uint8_t *buf, int buf_size)
+{
+ char fourcc_buf[5];
+ const int HEADER_SIZE = 37;
+ int icmp_offset = 0;
+
+ DNxUcParseContext *pc;
+ pc = (DNxUcParseContext *) s->priv_data;
+
+ if (!buf_size) {
+ return 0;
+ }
+ if (buf_size > 16 && MKTAG('i','c','m','p') == AV_RL32(buf+12)){
+ icmp_offset += 8;
+ }
+ if ( buf_size < 37 + icmp_offset /* check metadata structure expectations */
+ || MKTAG('p','a','c','k') != AV_RL32(buf+4+icmp_offset)
+ || MKTAG('s','i','n','f') != AV_RL32(buf+12+icmp_offset)
+ || MKTAG('s','d','a','t') != AV_RL32(buf+33+icmp_offset)){
+ av_log(avctx, AV_LOG_ERROR, "can't read DNxUncompressed metadata.\n");
+ *poutbuf_size = 0;
+ return buf_size;
+ }
+
+ pc->fourcc_tag = AV_RL32(buf+24+icmp_offset);
+ pc->width = AV_RL32(buf+16+icmp_offset);
+ pc->height = AV_RL32(buf+20+icmp_offset);
+ pc->nr_bytes = AV_RL32(buf+29+icmp_offset) - 8;
+
+ if (!avctx->codec_tag) {
+ av_fourcc_make_string(fourcc_buf, pc->fourcc_tag);
+ av_log(avctx, AV_LOG_INFO, "dnxuc_parser: '%s' %dx%d %dbpp %d\n",
+ fourcc_buf,
+ pc->width, pc->height,
+ (pc->nr_bytes*8)/(pc->width*pc->height),
+ pc->nr_bytes);
+ avctx->codec_tag = pc->fourcc_tag;
+ }
+
+ if (pc->nr_bytes > buf_size - HEADER_SIZE + icmp_offset){
+ av_log(avctx, AV_LOG_ERROR, "Insufficient size of image essence data.\n");
+ *poutbuf_size = 0;
+ return buf_size;
+ }
+
+ *poutbuf = buf + HEADER_SIZE + icmp_offset;
+ *poutbuf_size = pc->nr_bytes;
+
+ return buf_size;
+}
+
+const AVCodecParser ff_dnxuc_parser = {
+ .codec_ids = { AV_CODEC_ID_DNXUC },
+ .priv_data_size = sizeof(DNxUcParseContext),
+ .parser_parse = dnxuc_parse,
+};
diff --git a/libavcodec/parsers.c b/libavcodec/parsers.c
index 5128009..8bfd2db 100644
--- a/libavcodec/parsers.c
+++ b/libavcodec/parsers.c
@@ -35,6 +35,7 @@ extern const AVCodecParser ff_cri_parser;
extern const AVCodecParser ff_dca_parser;
extern const AVCodecParser ff_dirac_parser;
extern const AVCodecParser ff_dnxhd_parser;
+extern const AVCodecParser ff_dnxuc_parser;
extern const AVCodecParser ff_dolby_e_parser;
extern const AVCodecParser ff_dpx_parser;
extern const AVCodecParser ff_dvaudio_parser;
--
2.45.2
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