libavcodec/dnxuc_parser: DNxUncompressed essence parser

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/Makefile

@@ -1194,6 +1194,7 @@ 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

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,
+};

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;