avcodec: add Screen Recorder Gold Codec decoder

Signed-off-by: Paul B Mahol <onemda@gmail.com>

6 files changed, 32 insertions, 4 deletions

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 7398657dc4..3275654a45 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -541,6 +541,7 @@ OBJS-$(CONFIG_SONIC_ENCODER)           += sonic.o
 OBJS-$(CONFIG_SONIC_LS_ENCODER)        += sonic.o
 OBJS-$(CONFIG_SPEEDHQ_DECODER)         += speedhq.o simple_idct.o
 OBJS-$(CONFIG_SP5X_DECODER)            += sp5xdec.o
+OBJS-$(CONFIG_SRGC_DECODER)            += mscc.o
 OBJS-$(CONFIG_SRT_DECODER)             += srtdec.o ass.o htmlsubtitles.o
 OBJS-$(CONFIG_SRT_ENCODER)             += srtenc.o ass_split.o
 OBJS-$(CONFIG_STL_DECODER)             += textdec.o ass.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 5a708b3c3d..7fcc26f2c1 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -317,6 +317,7 @@ static void register_all(void)
     REGISTER_ENCDEC (SNOW,              snow);
     REGISTER_DECODER(SP5X,              sp5x);
     REGISTER_DECODER(SPEEDHQ,           speedhq);
+    REGISTER_DECODER(SRGC,              srgc);
     REGISTER_ENCDEC (SUNRAST,           sunrast);
     REGISTER_ENCDEC (SVQ1,              svq1);
     REGISTER_DECODER(SVQ3,              svq3);
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index da9d9dc256..fc928a1804 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -444,6 +444,7 @@ enum AVCodecID {
     AV_CODEC_ID_AV1,
     AV_CODEC_ID_BITPACKED,
     AV_CODEC_ID_MSCC,
+    AV_CODEC_ID_SRGC,
 
     /* various PCM "codecs" */
     AV_CODEC_ID_FIRST_AUDIO = 0x10000,     ///< A dummy id pointing at the start of audio codecs
diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
index e342db714d..2d28f840af 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -1395,6 +1395,13 @@ static const AVCodecDescriptor codec_descriptors[] = {
         .long_name = NULL_IF_CONFIG_SMALL("Mandsoft Screen Capture Codec"),
         .props     = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSLESS,
     },
+    {
+        .id        = AV_CODEC_ID_SRGC,
+        .type      = AVMEDIA_TYPE_VIDEO,
+        .name      = "srgc",
+        .long_name = NULL_IF_CONFIG_SMALL("Screen Recorder Gold Codec"),
+        .props     = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSLESS,
+    },
 
     /* image codecs */
     {
diff --git a/libavcodec/mscc.c b/libavcodec/mscc.c
index c42889ae73..6e4dbb014d 100644
--- a/libavcodec/mscc.c
+++ b/libavcodec/mscc.c
@@ -121,6 +121,8 @@ static int decode_frame(AVCodecContext *avctx,
 {
     MSCCContext *s = avctx->priv_data;
     AVFrame *frame = data;
+    uint8_t *buf = avpkt->data;
+    int buf_size = avpkt->size;
     GetByteContext gb;
     PutByteContext pb;
     int ret, j;
@@ -130,15 +132,19 @@ static int decode_frame(AVCodecContext *avctx,
     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
         return ret;
 
-    avpkt->data[2] ^= avpkt->data[0];
+    if (avctx->codec_id == AV_CODEC_ID_MSCC) {
+        avpkt->data[2] ^= avpkt->data[0];
+        buf += 2;
+        buf_size -= 2;
+    }
 
     ret = inflateReset(&s->zstream);
     if (ret != Z_OK) {
         av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
         return AVERROR_UNKNOWN;
     }
-    s->zstream.next_in   = avpkt->data + 2;
-    s->zstream.avail_in  = avpkt->size - 2;
+    s->zstream.next_in   = buf;
+    s->zstream.avail_in  = buf_size;
     s->zstream.next_out  = s->decomp_buf;
     s->zstream.avail_out = s->decomp_size;
     ret = inflate(&s->zstream, Z_FINISH);
@@ -229,3 +235,15 @@ AVCodec ff_mscc_decoder = {
     .decode           = decode_frame,
     .capabilities     = AV_CODEC_CAP_DR1,
 };
+
+AVCodec ff_srgc_decoder = {
+    .name             = "srgc",
+    .long_name        = NULL_IF_CONFIG_SMALL("Screen Recorder Gold Codec"),
+    .type             = AVMEDIA_TYPE_VIDEO,
+    .id               = AV_CODEC_ID_SRGC,
+    .priv_data_size   = sizeof(MSCCContext),
+    .init             = decode_init,
+    .close            = decode_close,
+    .decode           = decode_frame,
+    .capabilities     = AV_CODEC_CAP_DR1,
+};
diff --git a/libavcodec/version.h b/libavcodec/version.h
index cb238dc867..46872b0562 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -28,7 +28,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVCODEC_VERSION_MAJOR  57
-#define LIBAVCODEC_VERSION_MINOR  92
+#define LIBAVCODEC_VERSION_MINOR  93
 #define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \