[FFmpeg-cvslog] lavc: add null codecs
Anton Khirnov
git at videolan.org
Tue Jan 31 10:07:52 EET 2023
ffmpeg | branch: master | Anton Khirnov <anton at khirnov.net> | Fri Jan 27 18:41:40 2023 +0100| [e3a99041b80e915efc021f93eef1c3fddf41199c] | committer: Anton Khirnov
lavc: add null codecs
They discard all input without ever returning any output. Useful for
development.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=e3a99041b80e915efc021f93eef1c3fddf41199c
---
libavcodec/Makefile | 4 ++
libavcodec/allcodecs.c | 6 +++
libavcodec/codec_desc.c | 12 ++++++
libavcodec/codec_id.h | 10 +++++
libavcodec/null.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 129 insertions(+)
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 629933d85c..304c2bc2e3 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -219,6 +219,8 @@ OBJS-$(CONFIG_AMRWB_DECODER) += amrwbdec.o celp_filters.o \
acelp_pitch_delay.o
OBJS-$(CONFIG_AMV_ENCODER) += mjpegenc.o mjpegenc_common.o
OBJS-$(CONFIG_ANM_DECODER) += anm.o
+OBJS-$(CONFIG_ANULL_DECODER) += null.o
+OBJS-$(CONFIG_ANULL_ENCODER) += null.o
OBJS-$(CONFIG_ANSI_DECODER) += ansi.o cga_data.o
OBJS-$(CONFIG_APAC_DECODER) += apac.o
OBJS-$(CONFIG_APE_DECODER) += apedec.o
@@ -747,6 +749,8 @@ OBJS-$(CONFIG_VCR1_DECODER) += vcr1.o
OBJS-$(CONFIG_VMDAUDIO_DECODER) += vmdaudio.o
OBJS-$(CONFIG_VMDVIDEO_DECODER) += vmdvideo.o
OBJS-$(CONFIG_VMNC_DECODER) += vmnc.o
+OBJS-$(CONFIG_VNULL_DECODER) += null.o
+OBJS-$(CONFIG_VNULL_ENCODER) += null.o
OBJS-$(CONFIG_VORBIS_DECODER) += vorbisdec.o vorbisdsp.o vorbis.o \
vorbis_data.o
OBJS-$(CONFIG_VORBIS_ENCODER) += vorbisenc.o vorbis.o \
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 0deaea65b3..ff82423a88 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -884,6 +884,12 @@ extern const FFCodec ff_vp9_qsv_decoder;
extern const FFCodec ff_vp9_vaapi_encoder;
extern const FFCodec ff_vp9_qsv_encoder;
+// null codecs
+extern const FFCodec ff_vnull_decoder;
+extern const FFCodec ff_vnull_encoder;
+extern const FFCodec ff_anull_decoder;
+extern const FFCodec ff_anull_encoder;
+
// The iterate API is not usable with ossfuzz due to the excessive size of binaries created
#if CONFIG_OSSFUZZ
const FFCodec * codec_list[] = {
diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
index fbb6604f76..8ab228d846 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -3625,6 +3625,18 @@ static const AVCodecDescriptor codec_descriptors[] = {
.long_name = NULL_IF_CONFIG_SMALL("AVFrame to AVPacket passthrough"),
.props = AV_CODEC_PROP_LOSSLESS,
},
+ {
+ .id = AV_CODEC_ID_VNULL,
+ .type = AVMEDIA_TYPE_VIDEO,
+ .name = "vnull",
+ .long_name = NULL_IF_CONFIG_SMALL("Null video codec"),
+ },
+ {
+ .id = AV_CODEC_ID_ANULL,
+ .type = AVMEDIA_TYPE_AUDIO,
+ .name = "anull",
+ .long_name = NULL_IF_CONFIG_SMALL("Null audio codec"),
+ },
};
static int descriptor_compare(const void *key, const void *member)
diff --git a/libavcodec/codec_id.h b/libavcodec/codec_id.h
index 3e84098f35..0c574c9619 100644
--- a/libavcodec/codec_id.h
+++ b/libavcodec/codec_id.h
@@ -590,6 +590,16 @@ enum AVCodecID {
* stream (only used by libavformat) */
AV_CODEC_ID_FFMETADATA = 0x21000, ///< Dummy codec for streams containing only metadata information.
AV_CODEC_ID_WRAPPED_AVFRAME = 0x21001, ///< Passthrough codec, AVFrames wrapped in AVPacket
+ /**
+ * Dummy null video codec, useful mainly for development and debugging.
+ * Null encoder/decoder discard all input and never return any output.
+ */
+ AV_CODEC_ID_VNULL,
+ /**
+ * Dummy null audio codec, useful mainly for development and debugging.
+ * Null encoder/decoder discard all input and never return any output.
+ */
+ AV_CODEC_ID_ANULL,
};
/**
diff --git a/libavcodec/null.c b/libavcodec/null.c
new file mode 100644
index 0000000000..d8e334437c
--- /dev/null
+++ b/libavcodec/null.c
@@ -0,0 +1,97 @@
+/*
+ * Null codecs
+ *
+ * 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 "config_components.h"
+
+#include "codec_internal.h"
+#include "decode.h"
+#include "encode.h"
+
+#if CONFIG_VNULL_DECODER || CONFIG_ANULL_DECODER
+static int null_decode(AVCodecContext *avctx, AVFrame *frame,
+ int *got_frame, AVPacket *avpkt)
+{
+ *got_frame = 0;
+ return avpkt->size;
+}
+
+#if CONFIG_VNULL_DECODER
+const FFCodec ff_vnull_decoder = {
+ .p.name = "vnull",
+ CODEC_LONG_NAME("null video"),
+ .p.type = AVMEDIA_TYPE_VIDEO,
+ .p.id = AV_CODEC_ID_VNULL,
+ .p.capabilities = AV_CODEC_CAP_DR1,
+ FF_CODEC_DECODE_CB(null_decode),
+};
+#endif
+
+#if CONFIG_ANULL_DECODER
+const FFCodec ff_anull_decoder = {
+ .p.name = "anull",
+ CODEC_LONG_NAME("null audio"),
+ .p.type = AVMEDIA_TYPE_AUDIO,
+ .p.id = AV_CODEC_ID_ANULL,
+ .p.capabilities = AV_CODEC_CAP_DR1,
+ FF_CODEC_DECODE_CB(null_decode),
+};
+#endif
+
+#endif
+
+#if CONFIG_VNULL_ENCODER || CONFIG_ANULL_ENCODER
+static int null_encode(AVCodecContext *avctx, AVPacket *pkt,
+ const AVFrame *frame, int *got_packet)
+{
+ *got_packet = 0;
+ return 0;
+}
+
+#if CONFIG_VNULL_ENCODER
+const FFCodec ff_vnull_encoder = {
+ .p.name = "vnull",
+ CODEC_LONG_NAME("null video"),
+ .p.type = AVMEDIA_TYPE_VIDEO,
+ .p.id = AV_CODEC_ID_VNULL,
+ FF_CODEC_ENCODE_CB(null_encode),
+};
+#endif
+
+#if CONFIG_ANULL_ENCODER
+const FFCodec ff_anull_encoder = {
+ .p.name = "anull",
+ CODEC_LONG_NAME("null audio"),
+ .p.type = AVMEDIA_TYPE_AUDIO,
+ .p.id = AV_CODEC_ID_ANULL,
+ .p.capabilities = AV_CODEC_CAP_VARIABLE_FRAME_SIZE,
+ .p.sample_fmts = (const enum AVSampleFormat[]){
+ AV_SAMPLE_FMT_U8, AV_SAMPLE_FMT_U8P,
+ AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S16P,
+ AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_S32P,
+ AV_SAMPLE_FMT_S64, AV_SAMPLE_FMT_S64P,
+ AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_FLTP,
+ AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_DBLP,
+ AV_SAMPLE_FMT_NONE,
+ },
+ FF_CODEC_ENCODE_CB(null_encode),
+};
+#endif
+
+#endif
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