avcodec: add ClearVideo decoder

Only I-frames are decoded for now.

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

10 files changed, 403 insertions, 2 deletions

diff --git a/Changelog b/Changelog
index beb3486524..13628ca28b 100644
--- a/Changelog
+++ b/Changelog
@@ -25,6 +25,7 @@ version <next>:
 - FM Screen Capture Codec decoder
 - native Opus encoder
 - ScreenPressor decoder
+- incomplete ClearVideo decoder
 
 version 3.2:
 - libopenmpt demuxer
diff --git a/doc/general.texi b/doc/general.texi
index 626590ca76..30450c0cef 100644
--- a/doc/general.texi
+++ b/doc/general.texi
@@ -342,6 +342,7 @@ library:
 @item iLBC                      @tab X @tab X
 @item Interplay MVE             @tab   @tab X
     @tab Format used in various Interplay computer games.
+@item Iterated Systems ClearVideo @tab     @tab  X
 @item IV8                       @tab   @tab X
     @tab A format generated by IndigoVision 8000 video server.
 @item IVF (On2)                 @tab X @tab X
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 1bea44ad91..65ccbade8e 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -228,6 +228,7 @@ OBJS-$(CONFIG_CDXL_DECODER)            += cdxl.o
 OBJS-$(CONFIG_CFHD_DECODER)            += cfhd.o cfhddata.o
 OBJS-$(CONFIG_CINEPAK_DECODER)         += cinepak.o
 OBJS-$(CONFIG_CINEPAK_ENCODER)         += cinepakenc.o elbg.o
+OBJS-$(CONFIG_CLEARVIDEO_DECODER)      += clearvideo.o
 OBJS-$(CONFIG_CLJR_DECODER)            += cljrdec.o
 OBJS-$(CONFIG_CLJR_ENCODER)            += cljrenc.o
 OBJS-$(CONFIG_CLLC_DECODER)            += cllc.o canopus.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index eee322b2b8..a265ce5728 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -157,6 +157,7 @@ void avcodec_register_all(void)
     REGISTER_DECODER(CDXL,              cdxl);
     REGISTER_DECODER(CFHD,              cfhd);
     REGISTER_ENCDEC (CINEPAK,           cinepak);
+    REGISTER_DECODER(CLEARVIDEO,        clearvideo);
     REGISTER_ENCDEC (CLJR,              cljr);
     REGISTER_DECODER(CLLC,              cllc);
     REGISTER_ENCDEC (COMFORTNOISE,      comfortnoise);
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 298b9146e2..af054f3194 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -416,6 +416,7 @@ enum AVCodecID {
     AV_CODEC_ID_SPEEDHQ,
     AV_CODEC_ID_FMVC,
     AV_CODEC_ID_SCPR,
+    AV_CODEC_ID_CLEARVIDEO,
 
     /* various PCM "codecs" */
     AV_CODEC_ID_FIRST_AUDIO = 0x10000,     ///< A dummy id pointing at the start of audio codecs
diff --git a/libavcodec/clearvideo.c b/libavcodec/clearvideo.c
new file mode 100644
index 0000000000..91f37e1b62
--- /dev/null
+++ b/libavcodec/clearvideo.c
@@ -0,0 +1,387 @@
+/*
+ * ClearVideo decoder
+ * Copyright (c) 2012 Konstantin Shishkov
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * ClearVideo decoder
+ */
+
+#include "avcodec.h"
+#include "idctdsp.h"
+#include "internal.h"
+#include "get_bits.h"
+#include "bytestream.h"
+
+#define NUM_DC_CODES 127
+#define NUM_AC_CODES 103
+
+static const uint8_t clv_dc_codes[NUM_DC_CODES] = {
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
+    0x10, 0x11, 0x12, 0x13, 0x13, 0x14, 0x07, 0x0B,
+    0x0C, 0x08, 0x08, 0x09, 0x04, 0x06, 0x07, 0x05,
+    0x04, 0x05, 0x04, 0x06, 0x05, 0x06, 0x07, 0x05,
+    0x06, 0x07, 0x06, 0x07, 0x08, 0x06, 0x07, 0x08,
+    0x09, 0x0A, 0x0B, 0x07, 0x08, 0x09, 0x07, 0x08,
+    0x06, 0x07, 0x08, 0x06, 0x04, 0x05, 0x02, 0x01,
+    0x03, 0x06, 0x07, 0x07, 0x09, 0x0A, 0x0B, 0x09,
+    0x0A, 0x0B, 0x0A, 0x0B, 0x0C, 0x0D, 0x0C, 0x09,
+    0x0D, 0x0A, 0x0B, 0x08, 0x09, 0x0A, 0x0B, 0x07,
+    0x08, 0x09, 0x0A, 0x0B, 0x06, 0x07, 0x06, 0x08,
+    0x07, 0x09, 0x0A, 0x0B, 0x09, 0x0A, 0x0B, 0x0C,
+    0x14, 0x0D, 0x0D, 0x0E, 0x0F, 0x15, 0x15, 0x16,
+    0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E,
+    0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25,
+};
+
+static const uint8_t clv_dc_bits[NUM_DC_CODES] = {
+    22, 22, 22, 22, 22, 22, 22, 22,
+    22, 22, 22, 22, 22, 22, 22, 22,
+    22, 22, 22, 21, 22, 22, 19, 20,
+    20, 19, 18, 18, 15, 17, 17, 16,
+    14, 15, 12, 13, 14, 14, 14, 12,
+    12, 12, 11, 11, 11, 10, 10, 10,
+    10, 10, 10,  9,  9,  9,  8,  8,
+     7,  7,  7,  6,  5,  5,  3,  1,
+     3,  5,  5,  6,  7,  7,  7,  8,
+     8,  8,  9,  9,  9,  9, 10, 11,
+    10, 11, 11, 12, 12, 12, 12, 13,
+    14, 14, 14, 14, 15, 15, 16, 17,
+    16, 17, 18, 18, 19, 19, 19, 19,
+    21, 19, 20, 19, 19, 21, 22, 22,
+    22, 22, 22, 22, 22, 22, 22, 22,
+    22, 22, 22, 22, 22, 22, 22,
+};
+
+static const uint16_t clv_ac_syms[NUM_AC_CODES] = {
+    0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008,
+    0x0009, 0x000A, 0x000B, 0x000C, 0x0011, 0x0012, 0x0013, 0x0014,
+    0x0015, 0x0016, 0x0021, 0x0022, 0x0023, 0x0024, 0x0031, 0x0032,
+    0x0033, 0x0041, 0x0042, 0x0043, 0x0051, 0x0052, 0x0053, 0x0061,
+    0x0062, 0x0063, 0x0071, 0x0072, 0x0081, 0x0082, 0x0091, 0x0092,
+    0x00A1, 0x00A2, 0x00B1, 0x00C1, 0x00D1, 0x00E1, 0x00F1, 0x0101,
+    0x0111, 0x0121, 0x0131, 0x0141, 0x0151, 0x0161, 0x0171, 0x0181,
+    0x0191, 0x01A1, 0x1001, 0x1002, 0x1003, 0x1011, 0x1012, 0x1021,
+    0x1031, 0x1041, 0x1051, 0x1061, 0x1071, 0x1081, 0x1091, 0x10A1,
+    0x10B1, 0x10C1, 0x10D1, 0x10E1, 0x10F1, 0x1101, 0x1111, 0x1121,
+    0x1131, 0x1141, 0x1151, 0x1161, 0x1171, 0x1181, 0x1191, 0x11A1,
+    0x11B1, 0x11C1, 0x11D1, 0x11E1, 0x11F1, 0x1201, 0x1211, 0x1221,
+    0x1231, 0x1241, 0x1251, 0x1261, 0x1271, 0x1281, 0x1BFF,
+};
+
+static const uint8_t clv_ac_codes[NUM_AC_CODES] = {
+    0x02, 0x0F, 0x15, 0x17, 0x1F, 0x25, 0x24, 0x21,
+    0x20, 0x07, 0x06, 0x20, 0x06, 0x14, 0x1E, 0x0F,
+    0x21, 0x50, 0x0E, 0x1D, 0x0E, 0x51, 0x0D, 0x23,
+    0x0D, 0x0C, 0x22, 0x52, 0x0B, 0x0C, 0x53, 0x13,
+    0x0B, 0x54, 0x12, 0x0A, 0x11, 0x09, 0x10, 0x08,
+    0x16, 0x55, 0x15, 0x14, 0x1C, 0x1B, 0x21, 0x20,
+    0x1F, 0x1E, 0x1D, 0x1C, 0x1B, 0x1A, 0x22, 0x23,
+    0x56, 0x57, 0x07, 0x19, 0x05, 0x0F, 0x04, 0x0E,
+    0x0D, 0x0C, 0x13, 0x12, 0x11, 0x10, 0x1A, 0x19,
+    0x18, 0x17, 0x16, 0x15, 0x14, 0x13, 0x18, 0x17,
+    0x16, 0x15, 0x14, 0x13, 0x12, 0x11, 0x07, 0x06,
+    0x05, 0x04, 0x24, 0x25, 0x26, 0x27, 0x58, 0x59,
+    0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x03,
+};
+
+static const uint8_t clv_ac_bits[NUM_AC_CODES] = {
+     2,  4,  6,  7,  8,  9,  9, 10,
+    10, 11, 11, 11,  3,  6,  8, 10,
+    11, 12,  4,  8, 10, 12,  5,  9,
+    10,  5,  9, 12,  5, 10, 12,  6,
+    10, 12,  6, 10,  6, 10,  6, 10,
+     7, 12,  7,  7,  8,  8,  9,  9,
+     9,  9,  9,  9,  9,  9, 11, 11,
+    12, 12,  4,  9, 11,  6, 11,  6,
+     6,  6,  7,  7,  7,  7,  8,  8,
+     8,  8,  8,  8,  8,  8,  9,  9,
+     9,  9,  9,  9,  9,  9, 10, 10,
+    10, 10, 11, 11, 11, 11, 12, 12,
+    12, 12, 12, 12, 12, 12,  7,
+};
+
+typedef struct CLVContext {
+    AVCodecContext *avctx;
+    IDCTDSPContext idsp;
+    AVFrame        *pic;
+    GetBitContext  gb;
+    int            mb_width, mb_height;
+    VLC            dc_vlc, ac_vlc;
+    int            luma_dc_quant, chroma_dc_quant, ac_quant;
+    DECLARE_ALIGNED(16, int16_t, block)[64];
+    int            top_dc[3], left_dc[4];
+} CLVContext;
+
+static inline int decode_block(CLVContext *ctx, int16_t *blk, int has_ac,
+                               int ac_quant)
+{
+    GetBitContext *gb = &ctx->gb;
+    int idx = 1, last = 0, val, skip;
+
+    memset(blk, 0, sizeof(*blk) * 64);
+    blk[0] = get_vlc2(gb, ctx->dc_vlc.table, 9, 3);
+    if (blk[0] < 0)
+        return AVERROR_INVALIDDATA;
+    blk[0] -= 63;
+
+    if (!has_ac)
+        return 0;
+
+    while (idx < 64 && !last) {
+        val = get_vlc2(gb, ctx->ac_vlc.table, 9, 2);
+        if (val < 0)
+            return AVERROR_INVALIDDATA;
+        if (val != 0x1BFF) {
+            last =  val >> 12;
+            skip = (val >> 4) & 0xFF;
+            val &= 0xF;
+            if (get_bits1(gb))
+                val = -val;
+        } else {
+            last = get_bits1(gb);
+            skip = get_bits(gb, 6);
+            val  = get_sbits(gb, 8);
+        }
+        if (val) {
+            int aval = FFABS(val), sign = val < 0;
+            val = ac_quant * (2 * aval + 1);
+            if (!(ac_quant & 1))
+                val--;
+            if (sign)
+                val = -val;
+        }
+        idx += skip;
+        if (idx >= 64)
+            return AVERROR_INVALIDDATA;
+        blk[ff_zigzag_direct[idx++]] = val;
+    }
+
+    return (idx <= 64 && last) ? 0 : -1;
+}
+
+#define DCT_TEMPLATE(blk, step, bias, shift, dshift, OP)                \
+    const int t0 = OP( 2841 * blk[1 * step] +  565 * blk[7 * step]);    \
+    const int t1 = OP(  565 * blk[1 * step] - 2841 * blk[7 * step]);    \
+    const int t2 = OP( 1609 * blk[5 * step] + 2408 * blk[3 * step]);    \
+    const int t3 = OP( 2408 * blk[5 * step] - 1609 * blk[3 * step]);    \
+    const int t4 = OP( 1108 * blk[2 * step] - 2676 * blk[6 * step]);    \
+    const int t5 = OP( 2676 * blk[2 * step] + 1108 * blk[6 * step]);    \
+    const int t6 = ((blk[0 * step] + blk[4 * step]) << dshift) + bias;  \
+    const int t7 = ((blk[0 * step] - blk[4 * step]) << dshift) + bias;  \
+    const int t8 = t0 + t2;                                             \
+    const int t9 = t0 - t2;                                             \
+    const int tA = 181 * (t9 + (t1 - t3)) + 0x80 >> 8;                  \
+    const int tB = 181 * (t9 - (t1 - t3)) + 0x80 >> 8;                  \
+    const int tC = t1 + t3;                                             \
+                                                                        \
+    blk[0 * step] = (t6 + t5 + t8) >> shift;                            \
+    blk[1 * step] = (t7 + t4 + tA) >> shift;                            \
+    blk[2 * step] = (t7 - t4 + tB) >> shift;                            \
+    blk[3 * step] = (t6 - t5 + tC) >> shift;                            \
+    blk[4 * step] = (t6 - t5 - tC) >> shift;                            \
+    blk[5 * step] = (t7 - t4 - tB) >> shift;                            \
+    blk[6 * step] = (t7 + t4 - tA) >> shift;                            \
+    blk[7 * step] = (t6 + t5 - t8) >> shift;                            \
+
+#define ROP(x) x
+#define COP(x) (((x) + 4) >> 3)
+
+static void clv_dct(int16_t *block)
+{
+    int i;
+    int16_t *ptr;
+
+    ptr = block;
+    for (i = 0; i < 8; i++) {
+        DCT_TEMPLATE(ptr, 1, 0x80, 8, 11, ROP);
+        ptr += 8;
+    }
+
+    ptr = block;
+    for (i = 0; i < 8; i++) {
+        DCT_TEMPLATE(ptr, 8, 0x2000, 14, 8, COP);
+        ptr++;
+    }
+}
+
+static int decode_mb(CLVContext *c, int x, int y)
+{
+    int i;
+    int has_ac[6];
+    int off;
+
+    for (i = 0; i < 6; i++)
+        has_ac[i] = get_bits1(&c->gb);
+
+    off = x * 16 + y * 16 * c->pic->linesize[0];
+    for (i = 0; i < 4; i++) {
+        if (decode_block(c, c->block, has_ac[i], c->ac_quant) < 0)
+            return AVERROR_INVALIDDATA;
+        if (!x && !(i & 1)) {
+            c->block[0] += c->top_dc[0];
+            c->top_dc[0] = c->block[0];
+        } else {
+            c->block[0] += c->left_dc[(i & 2) >> 1];
+        }
+        c->left_dc[(i & 2) >> 1] = c->block[0];
+        c->block[0]             *= c->luma_dc_quant;
+        clv_dct(c->block);
+        if (i == 2)
+            off += c->pic->linesize[0] * 8;
+        c->idsp.put_pixels_clamped(c->block, c->pic->data[0] + off + (i & 1) * 8,
+                                   c->pic->linesize[0]);
+    }
+
+    off = x * 8 + y * 8 * c->pic->linesize[1];
+    for (i = 1; i < 3; i++) {
+        if (decode_block(c, c->block, has_ac[i + 3], c->ac_quant) < 0)
+            return AVERROR_INVALIDDATA;
+        if (!x) {
+            c->block[0] += c->top_dc[i];
+            c->top_dc[i] = c->block[0];
+        } else {
+            c->block[0] += c->left_dc[i + 1];
+        }
+        c->left_dc[i + 1] = c->block[0];
+        c->block[0]      *= c->chroma_dc_quant;
+        clv_dct(c->block);
+        c->idsp.put_pixels_clamped(c->block, c->pic->data[i] + off,
+                                   c->pic->linesize[i]);
+    }
+
+    return 0;
+}
+
+static int clv_decode_frame(AVCodecContext *avctx, void *data,
+                            int *got_frame, AVPacket *avpkt)
+{
+    const uint8_t *buf = avpkt->data;
+    int buf_size = avpkt->size;
+    CLVContext *c = avctx->priv_data;
+    GetByteContext gb;
+    uint32_t frame_type;
+    int i, j;
+    int ret;
+
+    bytestream2_init(&gb, buf, buf_size);
+    if (avctx->codec_tag == MKTAG('C','L','V','1')) {
+        int skip = bytestream2_get_byte(&gb);
+        bytestream2_skip(&gb, (skip + 1) * 8);
+    }
+
+    frame_type = bytestream2_get_byte(&gb);
+    if ((ret = ff_reget_buffer(avctx, c->pic)) < 0)
+        return ret;
+
+    c->pic->key_frame = frame_type & 0x20 ? 1 : 0;
+    c->pic->pict_type = frame_type & 0x20 ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
+
+    if (frame_type & 0x2) {
+        bytestream2_get_be32(&gb); // frame size;
+        c->ac_quant        = bytestream2_get_byte(&gb);
+        c->luma_dc_quant   = 32;
+        c->chroma_dc_quant = 32;
+
+        if ((ret = init_get_bits8(&c->gb, buf + bytestream2_tell(&gb),
+                                  (buf_size - bytestream2_tell(&gb)))) < 0)
+            return ret;
+
+        for (i = 0; i < 3; i++)
+            c->top_dc[i] = 32;
+        for (i = 0; i < 4; i++)
+            c->left_dc[i] = 32;
+
+        for (j = 0; j < c->mb_height; j++) {
+            for (i = 0; i < c->mb_width; i++) {
+                ret |= decode_mb(c, i, j);
+            }
+        }
+    } else {
+    }
+
+    if ((ret = av_frame_ref(data, c->pic)) < 0)
+        return ret;
+
+    *got_frame = 1;
+
+    return ret < 0 ? ret : buf_size;
+}
+
+static av_cold int clv_decode_init(AVCodecContext *avctx)
+{
+    CLVContext * const c = avctx->priv_data;
+    int ret;
+
+    c->avctx = avctx;
+
+    avctx->pix_fmt = AV_PIX_FMT_YUV420P;
+
+    c->pic = av_frame_alloc();
+    if (!c->pic)
+        return AVERROR(ENOMEM);
+
+    c->mb_width  = FFALIGN(avctx->width,  16) >> 4;
+    c->mb_height = FFALIGN(avctx->height, 16) >> 4;
+
+    ff_idctdsp_init(&c->idsp, avctx);
+    ret = init_vlc(&c->dc_vlc, 9, NUM_DC_CODES,
+                   clv_dc_bits,  1, 1,
+                   clv_dc_codes, 1, 1, 0);
+    if (ret) {
+        av_log(avctx, AV_LOG_ERROR, "Error initialising DC VLC\n");
+        return ret;
+    }
+    ret = ff_init_vlc_sparse(&c->ac_vlc, 9, NUM_AC_CODES,
+                             clv_ac_bits,  1, 1,
+                             clv_ac_codes, 1, 1,
+                             clv_ac_syms,  2, 2, 0);
+    if (ret) {
+        av_log(avctx, AV_LOG_ERROR, "Error initialising AC VLC\n");
+        return ret;
+    }
+
+    return 0;
+}
+
+static av_cold int clv_decode_end(AVCodecContext *avctx)
+{
+    CLVContext * const c = avctx->priv_data;
+
+    av_frame_free(&c->pic);
+
+    ff_free_vlc(&c->dc_vlc);
+    ff_free_vlc(&c->ac_vlc);
+
+    return 0;
+}
+
+AVCodec ff_clearvideo_decoder = {
+    .name           = "clearvideo",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = AV_CODEC_ID_CLEARVIDEO,
+    .priv_data_size = sizeof(CLVContext),
+    .init           = clv_decode_init,
+    .close          = clv_decode_end,
+    .decode         = clv_decode_frame,
+    .capabilities   = CODEC_CAP_DR1,
+    .long_name      = NULL_IF_CONFIG_SMALL("Iterated Systems ClearVideo"),
+};
diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
index 42935d7560..06bcfc3cce 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -1367,6 +1367,13 @@ static const AVCodecDescriptor codec_descriptors[] = {
         .long_name = NULL_IF_CONFIG_SMALL("ScreenPressor"),
         .props     = AV_CODEC_PROP_LOSSLESS | AV_CODEC_PROP_LOSSY,
     },
+    {
+        .id        = AV_CODEC_ID_CLEARVIDEO,
+        .type      = AVMEDIA_TYPE_VIDEO,
+        .name      = "clearvideo",
+        .long_name = NULL_IF_CONFIG_SMALL("Iterated Systems ClearVideo"),
+        .props     = AV_CODEC_PROP_LOSSY,
+    },
 
     /* image codecs */
     {
diff --git a/libavcodec/version.h b/libavcodec/version.h
index 5d8b22cb29..7647ad2e18 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -28,8 +28,8 @@
 #include "libavutil/version.h"
 
 #define LIBAVCODEC_VERSION_MAJOR  57
-#define LIBAVCODEC_VERSION_MINOR  81
-#define LIBAVCODEC_VERSION_MICRO 103
+#define LIBAVCODEC_VERSION_MINOR  82
+#define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
                                                LIBAVCODEC_VERSION_MINOR, \
diff --git a/libavformat/riff.c b/libavformat/riff.c
index e38c63632f..e3fb953622 100644
--- a/libavformat/riff.c
+++ b/libavformat/riff.c
@@ -450,6 +450,7 @@ const AVCodecTag ff_codec_bmp_tags[] = {
     { AV_CODEC_ID_SPEEDHQ,      MKTAG('S', 'H', 'Q', '9') },
     { AV_CODEC_ID_FMVC,         MKTAG('F', 'M', 'V', 'C') },
     { AV_CODEC_ID_SCPR,         MKTAG('S', 'C', 'P', 'R') },
+    { AV_CODEC_ID_CLEARVIDEO,   MKTAG('U', 'C', 'O', 'D') },
 
     { AV_CODEC_ID_NONE,         0 }
 };
diff --git a/libavformat/rm.c b/libavformat/rm.c
index 0591a1735a..52c7ccc1e8 100644
--- a/libavformat/rm.c
+++ b/libavformat/rm.c
@@ -43,5 +43,6 @@ const AVCodecTag ff_rm_codec_tags[] = {
     { AV_CODEC_ID_AAC,    MKTAG('r','a','a','c') },
     { AV_CODEC_ID_AAC,    MKTAG('r','a','c','p') },
     { AV_CODEC_ID_RALF,   MKTAG('L','S','D',':') },
+    { AV_CODEC_ID_CLEARVIDEO, MKTAG('C','L','V','1') },
     { AV_CODEC_ID_NONE },
 };