[FFmpeg-devel] avcodec: add RTV1 decoder

From cdd867aa1c88fa8b89dfe473ae0e2caf69c74313 Mon Sep 17 00:00:00 2001
From: Paul B Mahol <onemda@gmail.com>
Date: Sat, 3 Jun 2023 12:29:25 +0200
Subject: [PATCH] avcodec: add RTV1 decoder

Signed-off-by: Paul B Mahol <onemda@gmail.com>
---
 libavcodec/Makefile     |   1 +
 libavcodec/allcodecs.c  |   1 +
 libavcodec/codec_desc.c |   7 ++
 libavcodec/codec_id.h   |   1 +
 libavcodec/rtv1.c       | 141 ++++++++++++++++++++++++++++++++++++++++
 libavformat/riff.c      |   1 +
 6 files changed, 152 insertions(+)
 create mode 100644 libavcodec/rtv1.c

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 9aacc1d477..87a8b90037 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -643,6 +643,7 @@  OBJS-$(CONFIG_ROQ_DPCM_ENCODER)        += roqaudioenc.o
 OBJS-$(CONFIG_RPZA_DECODER)            += rpza.o
 OBJS-$(CONFIG_RPZA_ENCODER)            += rpzaenc.o
 OBJS-$(CONFIG_RSCC_DECODER)            += rscc.o
+OBJS-$(CONFIG_RTV1_DECODER)            += rtv1.o
 OBJS-$(CONFIG_RV10_DECODER)            += rv10.o
 OBJS-$(CONFIG_RV10_ENCODER)            += rv10enc.o
 OBJS-$(CONFIG_RV20_DECODER)            += rv10.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 184bb8521f..a98c300da4 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -295,6 +295,7 @@  extern const FFCodec ff_roq_decoder;
 extern const FFCodec ff_rpza_encoder;
 extern const FFCodec ff_rpza_decoder;
 extern const FFCodec ff_rscc_decoder;
+extern const FFCodec ff_rtv1_decoder;
 extern const FFCodec ff_rv10_encoder;
 extern const FFCodec ff_rv10_decoder;
 extern const FFCodec ff_rv20_encoder;
diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
index 310ed66415..41293a78dc 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -1946,6 +1946,13 @@  static const AVCodecDescriptor codec_descriptors[] = {
         .props     = AV_CODEC_PROP_LOSSY | AV_CODEC_PROP_REORDER,
         .profiles  = NULL_IF_CONFIG_SMALL(ff_evc_profiles),
     },
+    {
+        .id        = AV_CODEC_ID_RTV1,
+        .type      = AVMEDIA_TYPE_VIDEO,
+        .name      = "rtv1",
+        .long_name = NULL_IF_CONFIG_SMALL("RTV1 (RivaTuner Video)"),
+        .props     = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSY,
+    },
 
     /* various PCM "codecs" */
     {
diff --git a/libavcodec/codec_id.h b/libavcodec/codec_id.h
index 9f621afff0..9a78cfabe2 100644
--- a/libavcodec/codec_id.h
+++ b/libavcodec/codec_id.h
@@ -322,6 +322,7 @@  enum AVCodecID {
     AV_CODEC_ID_VQC,
     AV_CODEC_ID_PDV,
     AV_CODEC_ID_EVC,
+    AV_CODEC_ID_RTV1,
 
     /* various PCM "codecs" */
     AV_CODEC_ID_FIRST_AUDIO = 0x10000,     ///< A dummy id pointing at the start of audio codecs
diff --git a/libavcodec/rtv1.c b/libavcodec/rtv1.c
new file mode 100644
index 0000000000..953f915c83
--- /dev/null
+++ b/libavcodec/rtv1.c
@@ -0,0 +1,141 @@ 
+/*
+ * RTV1 decoder
+ * Copyright (c) 2023 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 <string.h>
+
+#include "avcodec.h"
+#include "bytestream.h"
+#include "codec_internal.h"
+#include "decode.h"
+#include "texturedsp.h"
+#include "thread.h"
+
+static int decode_rtv1(GetByteContext *gb, uint8_t *dst, int linesize,
+                       int width, int height, int flag,
+                       int (*dxt1_block)(uint8_t *dst, ptrdiff_t stride, const uint8_t *block))
+{
+    uint8_t block[8] = { 0 };
+    int run = 0;
+
+    for (int y = 0; y < height; y += 4) {
+        for (int x = 0; x < width * 4; x += 16) {
+            int mode = 0;
+
+            if (run && --run > 0) {
+                dxt1_block(dst + x, linesize, block);
+            } else {
+                int a, b;
+
+                if (bytestream2_get_bytes_left(gb) < 4)
+                    break;
+
+                a = bytestream2_get_le16u(gb);
+                b = bytestream2_get_le16u(gb);
+                if (a == b && flag) {
+                    AV_WL32(block + 4, 0);
+                } else if (a == 1 && b == 0xffff) {
+                    mode = 1;
+                } else if (b && a == 0) {
+                    run = b;
+                } else {
+                    AV_WL16(block,     a);
+                    AV_WL16(block + 2, b);
+                    AV_WL32(block + 4, bytestream2_get_le32(gb));
+                }
+                if (run && !mode) {
+                    dxt1_block(dst + x, linesize, block);
+                } else if (!mode) {
+                    AV_WL16(block,     a);
+                    AV_WL16(block + 2, b);
+                    dxt1_block(dst + x, linesize, block);
+                } else {
+                    if (bytestream2_get_bytes_left(gb) < 12 * 4)
+                        break;
+
+                    for (int by = 0; by < 4; by++) {
+                        for (int bx = 0; bx < 4; bx++)
+                            AV_WL32(dst + x + bx * 4 + by * linesize, bytestream2_get_le24u(gb));
+                    }
+                }
+            }
+        }
+
+        dst += linesize * 4;
+    }
+
+    return 0;
+}
+
+static int decode_frame(AVCodecContext *avctx, AVFrame *p,
+                        int *got_frame, AVPacket *avpkt)
+{
+    int ret, width, height, flags;
+    TextureDSPContext dsp;
+    GetByteContext gb;
+    ptrdiff_t linesize;
+    uint8_t *dst;
+
+    if (avpkt->size < 22)
+        return AVERROR_INVALIDDATA;
+
+    ff_texturedsp_init(&dsp);
+
+    bytestream2_init(&gb, avpkt->data, avpkt->size);
+
+    if (bytestream2_get_le32(&gb) != MKTAG('D','X','T','1'))
+        return AVERROR_INVALIDDATA;
+    flags = bytestream2_get_le32(&gb);
+
+    width = bytestream2_get_le32(&gb);
+    height = bytestream2_get_le32(&gb);
+    ret = ff_set_dimensions(avctx, width, height);
+    if (ret < 0)
+        return ret;
+
+    avctx->coded_width  = FFALIGN(avctx->width,  4);
+    avctx->coded_height = FFALIGN(avctx->height, 4);
+    avctx->pix_fmt = AV_PIX_FMT_BGR0;
+
+    if ((ret = ff_thread_get_buffer(avctx, p, 0)) < 0)
+        return ret;
+
+    dst = p->data[0] + p->linesize[0] * (avctx->coded_height - 1);
+    linesize = -p->linesize[0];
+
+    decode_rtv1(&gb, dst, linesize, width, height, flags, dsp.dxt1_block);
+
+    p->pict_type = AV_PICTURE_TYPE_I;
+    p->flags |= AV_FRAME_FLAG_KEY;
+
+    *got_frame = 1;
+
+    return avpkt->size;
+}
+
+const FFCodec ff_rtv1_decoder = {
+    .p.name           = "rtv1",
+    CODEC_LONG_NAME("RTV1 (RivaTuner Video)"),
+    .p.type           = AVMEDIA_TYPE_VIDEO,
+    .p.id             = AV_CODEC_ID_RTV1,
+    FF_CODEC_DECODE_CB(decode_frame),
+    .p.capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
+};
diff --git a/libavformat/riff.c b/libavformat/riff.c
index 7319406b39..4279071159 100644
--- a/libavformat/riff.c
+++ b/libavformat/riff.c
@@ -501,6 +501,7 @@  const AVCodecTag ff_codec_bmp_tags[] = {
     { AV_CODEC_ID_NOTCHLC,      MKTAG('n', 'l', 'c', '1') },
     { AV_CODEC_ID_VQC,          MKTAG('V', 'Q', 'C', '1') },
     { AV_CODEC_ID_VQC,          MKTAG('V', 'Q', 'C', '2') },
+    { AV_CODEC_ID_RTV1,         MKTAG('R', 'T', 'V', '1') },
     { AV_CODEC_ID_NONE,         0 }
 };
 
-- 
2.39.1