[FFmpeg-devel] [PATCH] avcodec: add MatchWare Screen Capture Codec
Paul B Mahol
onemda at gmail.com
Fri Aug 24 21:48:15 EEST 2018
Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
libavcodec/Makefile | 1 +
libavcodec/allcodecs.c | 1 +
libavcodec/avcodec.h | 1 +
libavcodec/codec_desc.c | 7 ++
libavcodec/mwsc.c | 174 ++++++++++++++++++++++++++++++++++++++++
libavformat/riff.c | 1 +
6 files changed, 185 insertions(+)
create mode 100644 libavcodec/mwsc.c
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 9a309c348e..aee4f5431a 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -482,6 +482,7 @@ OBJS-$(CONFIG_MSZH_DECODER) += lcldec.o
OBJS-$(CONFIG_MTS2_DECODER) += mss4.o
OBJS-$(CONFIG_MVC1_DECODER) += mvcdec.o
OBJS-$(CONFIG_MVC2_DECODER) += mvcdec.o
+OBJS-$(CONFIG_MWSC_DECODER) += mwsc.o
OBJS-$(CONFIG_MXPEG_DECODER) += mxpegdec.o
OBJS-$(CONFIG_NELLYMOSER_DECODER) += nellymoserdec.o nellymoser.o
OBJS-$(CONFIG_NELLYMOSER_ENCODER) += nellymoserenc.o nellymoser.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index b1d1ef26c0..d41868c591 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -212,6 +212,7 @@ extern AVCodec ff_mszh_decoder;
extern AVCodec ff_mts2_decoder;
extern AVCodec ff_mvc1_decoder;
extern AVCodec ff_mvc2_decoder;
+extern AVCodec ff_mwsc_decoder;
extern AVCodec ff_mxpeg_decoder;
extern AVCodec ff_nuv_decoder;
extern AVCodec ff_paf_video_decoder;
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 2a4be2ca4f..b327284449 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -449,6 +449,7 @@ enum AVCodecID {
AV_CODEC_ID_FITS,
AV_CODEC_ID_IMM4,
AV_CODEC_ID_PROSUMER,
+ AV_CODEC_ID_MWSC,
/* 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 e611183599..129d0f1aac 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -1668,6 +1668,13 @@ static const AVCodecDescriptor codec_descriptors[] = {
.long_name = NULL_IF_CONFIG_SMALL("Brooktree ProSumer Video"),
.props = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSY,
},
+ {
+ .id = AV_CODEC_ID_MWSC,
+ .type = AVMEDIA_TYPE_VIDEO,
+ .name = "mwsc",
+ .long_name = NULL_IF_CONFIG_SMALL("MatchWare Screen Capture Codec"),
+ .props = AV_CODEC_PROP_LOSSLESS,
+ },
/* various PCM "codecs" */
{
diff --git a/libavcodec/mwsc.c b/libavcodec/mwsc.c
new file mode 100644
index 0000000000..5ae8330500
--- /dev/null
+++ b/libavcodec/mwsc.c
@@ -0,0 +1,174 @@
+/*
+ * MatchWare Screen Capture Codec decoder
+ *
+ * Copyright (c) 2018 Paul B Mahol
+ *
+ * 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "avcodec.h"
+#include "bytestream.h"
+#include "internal.h"
+
+#include <zlib.h>
+
+typedef struct MWSCContext {
+ unsigned bpp;
+ unsigned int decomp_size;
+ uint8_t *decomp_buf;
+ unsigned int uncomp_size;
+ uint8_t *uncomp_buf;
+ z_stream zstream;
+} MWSCContext;
+
+static int rle_uncompress(AVCodecContext *avctx, GetByteContext *gb, PutByteContext *pb, int bpp)
+{
+ int intra = 1;
+
+ while (bytestream2_get_bytes_left(gb) > 0) {
+ uint32_t fill = bytestream2_get_le24(gb);
+ unsigned run = bytestream2_get_byte(gb);
+ int j;
+
+ if (run == 0) {
+ run = bytestream2_get_le32(gb);
+ for (j = 0; j < run; j++) {
+ bytestream2_put_le24(pb, fill);
+ }
+ } else if (run == 255) {
+ bytestream2_skip_p(pb, fill * 3);
+ intra = 0;
+ } else {
+ for (j = 0; j < run; j++) {
+ bytestream2_put_le24(pb, fill);
+ }
+ }
+ }
+
+ return intra;
+}
+
+static int decode_frame(AVCodecContext *avctx,
+ void *data, int *got_frame,
+ AVPacket *avpkt)
+{
+ MWSCContext *s = avctx->priv_data;
+ AVFrame *frame = data;
+ uint8_t *buf = avpkt->data;
+ int buf_size = avpkt->size;
+ GetByteContext gb;
+ PutByteContext pb;
+ int ret, j;
+
+ 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 = 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);
+ if (ret != Z_STREAM_END) {
+ av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", ret);
+ return AVERROR_UNKNOWN;
+ }
+
+ bytestream2_init(&gb, s->decomp_buf, s->zstream.total_out);
+ bytestream2_init_writer(&pb, s->uncomp_buf, s->uncomp_size);
+
+ frame->key_frame = rle_uncompress(avctx, &gb, &pb, s->bpp);
+
+ if ((ret = ff_reget_buffer(avctx, frame)) < 0)
+ return ret;
+
+ for (j = 0; j < avctx->height; j++) {
+ memcpy(frame->data[0] + (avctx->height - j - 1) * frame->linesize[0],
+ s->uncomp_buf + s->bpp * j * avctx->width, s->bpp * avctx->width);
+ }
+
+ frame->pict_type = frame->key_frame ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
+
+ *got_frame = 1;
+
+ return avpkt->size;
+}
+
+static av_cold int decode_init(AVCodecContext *avctx)
+{
+ MWSCContext *s = avctx->priv_data;
+ int zret;
+
+ switch (avctx->bits_per_coded_sample) {
+ case 24: avctx->pix_fmt = AV_PIX_FMT_BGR24; break;
+ default:
+ av_log(avctx, AV_LOG_ERROR, "Unsupported bitdepth %i\n", avctx->bits_per_coded_sample);
+ return AVERROR_INVALIDDATA;
+ }
+
+ s->bpp = avctx->bits_per_coded_sample >> 3;
+ memset(&s->zstream, 0, sizeof(z_stream));
+
+ s->decomp_size = 8 * avctx->height * ((avctx->width * avctx->bits_per_coded_sample + 31) / 32);
+ if (!(s->decomp_buf = av_malloc(s->decomp_size)))
+ return AVERROR(ENOMEM);
+
+ s->uncomp_size = 4 * avctx->height * ((avctx->width * avctx->bits_per_coded_sample + 31) / 32);
+ if (!(s->uncomp_buf = av_malloc(s->uncomp_size)))
+ return AVERROR(ENOMEM);
+
+ s->zstream.zalloc = Z_NULL;
+ s->zstream.zfree = Z_NULL;
+ s->zstream.opaque = Z_NULL;
+ zret = inflateInit(&s->zstream);
+ if (zret != Z_OK) {
+ av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
+ return AVERROR_UNKNOWN;
+ }
+
+ return 0;
+}
+
+static av_cold int decode_close(AVCodecContext *avctx)
+{
+ MWSCContext *s = avctx->priv_data;
+
+ av_freep(&s->decomp_buf);
+ s->decomp_size = 0;
+ av_freep(&s->uncomp_buf);
+ s->uncomp_size = 0;
+ inflateEnd(&s->zstream);
+
+ return 0;
+}
+
+AVCodec ff_mwsc_decoder = {
+ .name = "mwsc",
+ .long_name = NULL_IF_CONFIG_SMALL("MatchWare Screen Capture Codec"),
+ .type = AVMEDIA_TYPE_VIDEO,
+ .id = AV_CODEC_ID_MWSC,
+ .priv_data_size = sizeof(MWSCContext),
+ .init = decode_init,
+ .close = decode_close,
+ .decode = decode_frame,
+ .capabilities = AV_CODEC_CAP_DR1,
+};
diff --git a/libavformat/riff.c b/libavformat/riff.c
index cf27d0dfd5..aef3c047ac 100644
--- a/libavformat/riff.c
+++ b/libavformat/riff.c
@@ -472,6 +472,7 @@ const AVCodecTag ff_codec_bmp_tags[] = {
{ AV_CODEC_ID_SRGC, MKTAG('S', 'R', 'G', 'C') },
{ AV_CODEC_ID_IMM4, MKTAG('I', 'M', 'M', '4') },
{ AV_CODEC_ID_PROSUMER, MKTAG('B', 'T', '2', '0') },
+ { AV_CODEC_ID_MWSC, MKTAG('M', 'W', 'S', 'C') },
{ AV_CODEC_ID_NONE, 0 }
};
--
2.17.1
More information about the ffmpeg-devel
mailing list