[FFmpeg-devel] [PATCH] avcodec: Add dv marker bsf

Michael Niedermayer michael at niedermayer.cc
Tue Mar 8 01:17:43 EET 2022


Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 doc/bitstream_filters.texi       |  15 ++++
 libavcodec/Makefile              |   1 +
 libavcodec/bitstream_filters.c   |   1 +
 libavcodec/dv_error_marker_bsf.c | 117 +++++++++++++++++++++++++++++++
 4 files changed, 134 insertions(+)
 create mode 100644 libavcodec/dv_error_marker_bsf.c

diff --git a/doc/bitstream_filters.texi b/doc/bitstream_filters.texi
index a0092878c8..6a882ade97 100644
--- a/doc/bitstream_filters.texi
+++ b/doc/bitstream_filters.texi
@@ -132,6 +132,21 @@ the header stored in extradata to the key packets:
 ffmpeg -i INPUT -map 0 -flags:v +global_header -c:v libx264 -bsf:v dump_extra out.ts
 @end example
 
+ at section dv_error_marker
+
+Blocks in DV which are marked as damaged are replaced by blocks of the specified color.
+
+ at table @option
+ at item color
+The color to replace damaged blocks by
+ at item sta
+The error status to replace. If -1 then the stamask is used. -1 is the default.
+ at item stamask
+A 16 bit mask which specifies which of the 16 possible error status values are
+to be replaced by colored blocks. 0xFFFE is the default which replaces all non 0
+error status values.
+ at end table
+
 @section eac3_core
 
 Extract the core from a E-AC-3 stream, dropping extra channels.
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index bfc31bacd4..c5ed46f121 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -1161,6 +1161,7 @@ OBJS-$(CONFIG_AV1_FRAME_SPLIT_BSF)        += av1_frame_split_bsf.o
 OBJS-$(CONFIG_CHOMP_BSF)                  += chomp_bsf.o
 OBJS-$(CONFIG_DUMP_EXTRADATA_BSF)         += dump_extradata_bsf.o
 OBJS-$(CONFIG_DCA_CORE_BSF)               += dca_core_bsf.o
+OBJS-$(CONFIG_DV_ERROR_MARKER_BSF)        += dv_error_marker_bsf.o
 OBJS-$(CONFIG_EAC3_CORE_BSF)              += eac3_core_bsf.o
 OBJS-$(CONFIG_EXTRACT_EXTRADATA_BSF)      += extract_extradata_bsf.o    \
                                              av1_parse.o h2645_parse.o
diff --git a/libavcodec/bitstream_filters.c b/libavcodec/bitstream_filters.c
index d565286397..ab27972a88 100644
--- a/libavcodec/bitstream_filters.c
+++ b/libavcodec/bitstream_filters.c
@@ -31,6 +31,7 @@ extern const AVBitStreamFilter ff_av1_metadata_bsf;
 extern const AVBitStreamFilter ff_chomp_bsf;
 extern const AVBitStreamFilter ff_dump_extradata_bsf;
 extern const AVBitStreamFilter ff_dca_core_bsf;
+extern const AVBitStreamFilter ff_dv_error_marker_bsf;
 extern const AVBitStreamFilter ff_eac3_core_bsf;
 extern const AVBitStreamFilter ff_extract_extradata_bsf;
 extern const AVBitStreamFilter ff_filter_units_bsf;
diff --git a/libavcodec/dv_error_marker_bsf.c b/libavcodec/dv_error_marker_bsf.c
new file mode 100644
index 0000000000..31c0fb8da6
--- /dev/null
+++ b/libavcodec/dv_error_marker_bsf.c
@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2022 Michael Niedermayer
+ *
+ * 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 "bsf.h"
+#include "bsf_internal.h"
+#include "libavutil/colorspace.h"
+#include "libavutil/intreadwrite.h"
+#include "libavutil/opt.h"
+
+typedef struct DVErrorMarkerContext {
+    const AVClass *class;
+    uint8_t color_rgba[4];
+    int sta;
+    int stamask;
+    uint8_t marked_block[76];
+} DVErrorMarkerContext;
+
+static int dv_error_marker_init(AVBSFContext *ctx)
+{
+    DVErrorMarkerContext *s = ctx->priv_data;
+    int i;
+
+    memset(s->marked_block, -1, 76);
+    for (i=0; i<4; i++) {
+        s->marked_block[14*i  ] = RGB_TO_Y_JPEG(s->color_rgba[0], s->color_rgba[1],s->color_rgba[2]) + 128;
+        s->marked_block[14*i+1] = 0x06;
+    }
+    s->marked_block[4*14 + 10*0  ] = RGB_TO_V_JPEG(s->color_rgba[0], s->color_rgba[1],s->color_rgba[2]) - 128;
+    s->marked_block[4*14 + 10*0+1] = 0x16;
+    s->marked_block[4*14 + 10*1  ] = RGB_TO_U_JPEG(s->color_rgba[0], s->color_rgba[1],s->color_rgba[2]) - 128;
+    s->marked_block[4*14 + 10*1+1] = 0x16;
+
+    return 0;
+}
+
+static int dv_error_marker_filter(AVBSFContext *ctx, AVPacket *pkt)
+{
+    DVErrorMarkerContext *s = ctx->priv_data;
+    int ret = ff_bsf_get_packet_ref(ctx, pkt);
+    uint8_t *p;
+    int writable = 0;
+    int stamask;
+    int match_count = 0;
+
+    if (ret < 0)
+        return ret;
+
+    if (s->sta >= 0) {
+        stamask = 1 << s->sta;
+    } else
+        stamask = s->stamask;
+
+    p = pkt->data;
+    for(int i = 0; i < pkt->size - 79; i+=80) {
+        // see page 44-46 or section 5.5 of http://web.archive.org/web/20060927044735/http://www.smpte.org/smpte_store/standards/pdf/s314m.pdf.
+        if ((p[i] >> 4) == 9 && ((stamask >> (p[i+3] >> 4))&1)) {
+            if (!writable) {
+                ret = av_packet_make_writable(pkt);
+                if (ret < 0) {
+                    av_packet_unref(pkt);
+                    return ret;
+                }
+                writable = 1;
+                p = pkt->data;
+            }
+            memcpy(p+i+4, s->marked_block, 76);
+            match_count ++;
+        }
+    }
+    av_log(ctx, AV_LOG_DEBUG, "%8"PRId64": Replaced %5d blocks by color %X\n", pkt->pts, match_count, AV_RB32(s->color_rgba));
+
+    return 0;
+}
+
+#define OFFSET(x) offsetof(DVErrorMarkerContext, x)
+#define FLAGS (AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_BSF_PARAM)
+static const AVOption options[] = {
+    { "color"  , "set color", OFFSET(color_rgba), AV_OPT_TYPE_COLOR, {.str = "yellow"}, 0,      0, FLAGS },
+    { "stamask", "bitmask to specify which error status values to match"
+                            , OFFSET(stamask   ), AV_OPT_TYPE_INT  , {.i64 =   0xFFFE}, 0, 0xFFFF, FLAGS },
+    { "sta"    , "specify which error status value to match"
+                            , OFFSET(sta       ), AV_OPT_TYPE_INT  , {.i64 =       -1},-1,     15, FLAGS },
+    { NULL },
+};
+
+static const AVClass dv_error_marker_class = {
+    .class_name = "dv_error_marker",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+const AVBitStreamFilter ff_dv_error_marker_bsf = {
+    .name           = "dv_error_marker",
+    .priv_data_size = sizeof(DVErrorMarkerContext),
+    .priv_class     = &dv_error_marker_class,
+    .init           = dv_error_marker_init,
+    .filter         = dv_error_marker_filter,
+    .codec_ids      =  (const enum AVCodecID []){ AV_CODEC_ID_DVVIDEO, AV_CODEC_ID_NONE },
+};
-- 
2.17.1



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