[FFmpeg-devel] [PATCH] lavc: add null codecs
Anton Khirnov
anton at khirnov.net
Fri Jan 27 20:44:15 EET 2023
They discard all input without ever returning any output. Useful for
development.
---
libavcodec/Makefile | 4 ++
libavcodec/allcodecs.c | 6 +++
libavcodec/codec_desc.c | 12 ++++++
libavcodec/codec_id.h | 10 +++++
libavcodec/null.c | 96 +++++++++++++++++++++++++++++++++++++++++
libavcodec/version.h | 2 +-
6 files changed, 129 insertions(+), 1 deletion(-)
create mode 100644 libavcodec/null.c
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 2d9710923d..098ab18353 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
@@ -746,6 +748,8 @@ 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 f728c6c82e..7452002f24 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -882,6 +882,12 @@ 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 2272232ed6..b3bec2f659 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -1923,6 +1923,12 @@ static const AVCodecDescriptor codec_descriptors[] = {
.long_name = NULL_IF_CONFIG_SMALL("ViewQuest VQC"),
.props = AV_CODEC_PROP_LOSSY,
},
+ {
+ .id = AV_CODEC_ID_VNULL,
+ .type = AVMEDIA_TYPE_VIDEO,
+ .name = "vnull",
+ .long_name = NULL_IF_CONFIG_SMALL("Null video codec"),
+ },
/* various PCM "codecs" */
{
@@ -3339,6 +3345,12 @@ static const AVCodecDescriptor codec_descriptors[] = {
.long_name = NULL_IF_CONFIG_SMALL("FTR Voice"),
.props = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSY,
},
+ {
+ .id = AV_CODEC_ID_ANULL,
+ .type = AVMEDIA_TYPE_AUDIO,
+ .name = "anull",
+ .long_name = NULL_IF_CONFIG_SMALL("Null audio codec"),
+ },
/* subtitle codecs */
{
diff --git a/libavcodec/codec_id.h b/libavcodec/codec_id.h
index 5ec3fd4b30..c197e956b7 100644
--- a/libavcodec/codec_id.h
+++ b/libavcodec/codec_id.h
@@ -320,6 +320,11 @@ enum AVCodecID {
AV_CODEC_ID_WBMP,
AV_CODEC_ID_MEDIA100,
AV_CODEC_ID_VQC,
+ /**
+ * 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,
/* various PCM "codecs" */
AV_CODEC_ID_FIRST_AUDIO = 0x10000, ///< A dummy id pointing at the start of audio codecs
@@ -534,6 +539,11 @@ enum AVCodecID {
AV_CODEC_ID_MISC4,
AV_CODEC_ID_APAC,
AV_CODEC_ID_FTR,
+ /**
+ * 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,
/* subtitle codecs */
AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs.
diff --git a/libavcodec/null.c b/libavcodec/null.c
new file mode 100644
index 0000000000..df75a077ae
--- /dev/null
+++ b/libavcodec/null.c
@@ -0,0 +1,96 @@
+/*
+ * 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,
+ },
+ FF_CODEC_ENCODE_CB(null_encode),
+};
+#endif
+
+#endif
diff --git a/libavcodec/version.h b/libavcodec/version.h
index dfd3d5d7e5..7ac8d2b2fe 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -29,7 +29,7 @@
#include "version_major.h"
-#define LIBAVCODEC_VERSION_MINOR 57
+#define LIBAVCODEC_VERSION_MINOR 58
#define LIBAVCODEC_VERSION_MICRO 100
#define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
--
2.35.1
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