X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Fdnxhddec.c;h=c61e2df1f88527d419a06ef88ad25507a3960783;hb=cac4760bf42f1b7ec93860399fbb7b5bff90005f;hp=36232be1b7f9b6e8b4b024bc4cdabbff351a1b25;hpb=52b6bad21992e71dd92e3a91522acf1525a76307;p=ffmpeg

diff --git a/libavcodec/dnxhddec.c b/libavcodec/dnxhddec.c
index 36232be1b7f..c61e2df1f88 100644
--- a/libavcodec/dnxhddec.c
+++ b/libavcodec/dnxhddec.c
@@ -1,50 +1,37 @@
 /*
  * VC3/DNxHD decoder.
- * Copyright (c) 2007 SmartJog S.A., Baptiste Coudurier <baptiste dot coudurier at smartjog dot com>.
+ * Copyright (c) 2007 SmartJog S.A., Baptiste Coudurier <baptiste dot coudurier at smartjog dot com>
+ * Copyright (c) 2011 MirriAd Ltd
  *
- * This file is part of FFmpeg.
+ * 10 bit support added by MirriAd Ltd, Joseph Artsimovich <joseph@mirriad.com>
  *
- * FFmpeg is free software; you can redistribute it and/or
+ * This file is part of Libav.
+ *
+ * Libav 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,
+ * Libav 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
+ * License along with Libav; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 //#define TRACE
 //#define DEBUG
 
+#include "libavutil/imgutils.h"
 #include "avcodec.h"
-#include "bitstream.h"
+#include "get_bits.h"
 #include "dnxhddata.h"
 #include "dsputil.h"
-#include "mpegvideo.h"
 
-typedef struct {
-    int cid;
-    unsigned int width, height;
-    int interlaced;
-    unsigned int frame_size;
-    int index_bits;
-    int bit_depth;
-    const uint8_t *luma_weigth, *chroma_weigth;
-    const uint8_t *dc_codes, *dc_bits;
-    const uint16_t *ac_codes;
-    const uint8_t *ac_bits, *ac_level;
-    const uint8_t *ac_run_flag, *ac_index_flag;
-    const uint16_t *run_codes;
-    const uint8_t *run_bits, *run;
-} CIDEntry;
-
-typedef struct {
+typedef struct DNXHDContext {
     AVCodecContext *avctx;
     AVFrame picture;
     GetBitContext gb;
@@ -53,94 +40,69 @@ typedef struct {
     unsigned int mb_width, mb_height;
     uint32_t mb_scan_index[68];         /* max for 1080p */
     int cur_field;                      ///< current interlaced field
-    int index_bits;                     ///< length of index value
     VLC ac_vlc, dc_vlc, run_vlc;
-    const uint8_t *ac_level, *run;
-    const uint8_t *ac_run_flag, *ac_index_flag;
-    const uint8_t *luma_weigth, *chroma_weigth;
     int last_dc[3];
     DSPContext dsp;
-    DECLARE_ALIGNED_16(DCTELEM, blocks[8][64]);
-    DECLARE_ALIGNED_8(ScanTable, scantable);
+    DECLARE_ALIGNED(16, DCTELEM, blocks)[8][64];
+    ScanTable scantable;
     const CIDEntry *cid_table;
+    int bit_depth; // 8, 10 or 0 if not initialized at all.
+    void (*decode_dct_block)(struct DNXHDContext *ctx, DCTELEM *block,
+                             int n, int qscale);
 } DNXHDContext;
 
-static const CIDEntry cid_table[] = {
-    { 1238, 1920, 1080, 0, 917504, 4, 8,
-      dnxhd_1238_luma_weigth, dnxhd_1238_chroma_weigth,
-      dnxhd_1238_dc_codes, dnxhd_1238_dc_bits,
-      dnxhd_1238_ac_codes, dnxhd_1238_ac_bits, dnxhd_1238_ac_level,
-      dnxhd_1238_ac_run_flag, dnxhd_1238_ac_index_flag,
-      dnxhd_1238_run_codes, dnxhd_1238_run_bits, dnxhd_1238_run },
-/*     { 1243, 1920, 1080, 1, 917504, 4, 8, */
-/*       dnxhd_1243_luma_weigth, dnxhd_1243_chroma_weigth, */
-/*       dnxhd_1238_dc_codes, dnxhd_1238_dc_bits, */
-/*       dnxhd_1238_ac_codes, dnxhd_1238_ac_bits, dnxhd_1238_ac_level, */
-/*       dnxhd_1238_ac_run_flag, dnxhd_1238_ac_index_flag, */
-/*       dnxhd_1238_run_codes, dnxhd_1238_run_bits, dnxhd_1238_run }, */
-};
-
-static int dnxhd_get_cid_table(int cid)
-{
-    int i;
-    for (i = 0; i < sizeof(cid_table)/sizeof(CIDEntry); i++)
-        if (cid_table[i].cid == cid)
-            return i;
-    return -1;
-}
-
 #define DNXHD_VLC_BITS 9
-#define DNXHD_DC_VLC_BITS 6
+#define DNXHD_DC_VLC_BITS 7
 
-static int dnxhd_decode_init(AVCodecContext *avctx)
+static void dnxhd_decode_dct_block_8(DNXHDContext *ctx, DCTELEM *block, int n, int qscale);
+static void dnxhd_decode_dct_block_10(DNXHDContext *ctx, DCTELEM *block, int n, int qscale);
+
+static av_cold int dnxhd_decode_init(AVCodecContext *avctx)
 {
     DNXHDContext *ctx = avctx->priv_data;
 
     ctx->avctx = avctx;
-    dsputil_init(&ctx->dsp, avctx);
     avctx->coded_frame = &ctx->picture;
-    ctx->picture.type = FF_I_TYPE;
+    ctx->picture.type = AV_PICTURE_TYPE_I;
+    ctx->picture.key_frame = 1;
     return 0;
 }
 
 static int dnxhd_init_vlc(DNXHDContext *ctx, int cid)
 {
-    if (!ctx->cid_table) {
+    if (cid != ctx->cid) {
         int index;
 
-        if ((index = dnxhd_get_cid_table(cid)) < 0) {
+        if ((index = ff_dnxhd_get_cid_table(cid)) < 0) {
             av_log(ctx->avctx, AV_LOG_ERROR, "unsupported cid %d\n", cid);
             return -1;
         }
-        ctx->cid_table = &cid_table[index];
-        init_vlc(&ctx->ac_vlc, DNXHD_VLC_BITS, 257,
-                 cid_table->ac_bits, 1, 1,
-                 cid_table->ac_codes, 2, 2, 0);
-        init_vlc(&ctx->dc_vlc, DNXHD_DC_VLC_BITS, 12,
-                 cid_table->dc_bits, 1, 1,
-                 cid_table->dc_codes, 1, 1, 0);
-        init_vlc(&ctx->run_vlc, DNXHD_VLC_BITS, 62,
-                 cid_table->run_bits, 1, 1,
-                 cid_table->run_codes, 2, 2, 0);
+        ctx->cid_table = &ff_dnxhd_cid_table[index];
 
-        ctx->run           = cid_table->run;
-        ctx->ac_level      = cid_table->ac_level;
-        ctx->ac_run_flag   = cid_table->ac_run_flag;
-        ctx->ac_index_flag = cid_table->ac_index_flag;
-        ctx->luma_weigth   = cid_table->luma_weigth;
-        ctx->chroma_weigth = cid_table->chroma_weigth;
+        ff_free_vlc(&ctx->ac_vlc);
+        ff_free_vlc(&ctx->dc_vlc);
+        ff_free_vlc(&ctx->run_vlc);
 
-        ctx->index_bits = cid_table->index_bits;
+        init_vlc(&ctx->ac_vlc, DNXHD_VLC_BITS, 257,
+                 ctx->cid_table->ac_bits, 1, 1,
+                 ctx->cid_table->ac_codes, 2, 2, 0);
+        init_vlc(&ctx->dc_vlc, DNXHD_DC_VLC_BITS, ctx->bit_depth + 4,
+                 ctx->cid_table->dc_bits, 1, 1,
+                 ctx->cid_table->dc_codes, 1, 1, 0);
+        init_vlc(&ctx->run_vlc, DNXHD_VLC_BITS, 62,
+                 ctx->cid_table->run_bits, 1, 1,
+                 ctx->cid_table->run_codes, 2, 2, 0);
 
         ff_init_scantable(ctx->dsp.idct_permutation, &ctx->scantable, ff_zigzag_direct);
+        ctx->cid = cid;
     }
     return 0;
 }
 
-static int dnxhd_decode_header(DNXHDContext *ctx, uint8_t *buf, int buf_size)
+static int dnxhd_decode_header(DNXHDContext *ctx, const uint8_t *buf, int buf_size, int first_field)
 {
     static const uint8_t header_prefix[] = { 0x00, 0x00, 0x02, 0x80, 0x01 };
-    int i;
+    int i, cid;
 
     if (buf_size < 0x280)
         return -1;
@@ -149,28 +111,43 @@ static int dnxhd_decode_header(DNXHDContext *ctx, uint8_t *buf, int buf_size)
         av_log(ctx->avctx, AV_LOG_ERROR, "error in header\n");
         return -1;
     }
-    if (buf[5] & 2) {/* interlaced FIXME top or bottom */
+    if (buf[5] & 2) { /* interlaced */
+        ctx->cur_field = buf[5] & 1;
         ctx->picture.interlaced_frame = 1;
-        av_log(ctx->avctx, AV_LOG_DEBUG, "interlaced %d\n", buf[5] & 3);
+        ctx->picture.top_field_first = first_field ^ ctx->cur_field;
+        av_log(ctx->avctx, AV_LOG_DEBUG, "interlaced %d, cur field %d\n", buf[5] & 3, ctx->cur_field);
     }
 
     ctx->height = AV_RB16(buf + 0x18);
     ctx->width  = AV_RB16(buf + 0x1a);
 
-    dprintf(ctx->avctx, AV_LOG_DEBUG, "width %d, heigth %d\n", ctx->width, ctx->height);
+    av_dlog(ctx->avctx, "width %d, height %d\n", ctx->width, ctx->height);
 
-    if (buf[0x21] & 0x80) {
-        av_log(ctx->avctx, AV_LOG_ERROR, "10 bit per component\n");
-        return -1;
+    if (buf[0x21] & 0x40) {
+        ctx->avctx->pix_fmt = PIX_FMT_YUV422P10;
+        ctx->avctx->bits_per_raw_sample = 10;
+        if (ctx->bit_depth != 10) {
+            ff_dsputil_init(&ctx->dsp, ctx->avctx);
+            ctx->bit_depth = 10;
+            ctx->decode_dct_block = dnxhd_decode_dct_block_10;
+        }
+    } else {
+        ctx->avctx->pix_fmt = PIX_FMT_YUV422P;
+        ctx->avctx->bits_per_raw_sample = 8;
+        if (ctx->bit_depth != 8) {
+            ff_dsputil_init(&ctx->dsp, ctx->avctx);
+            ctx->bit_depth = 8;
+            ctx->decode_dct_block = dnxhd_decode_dct_block_8;
+        }
     }
 
-    ctx->cid = AV_RB32(buf + 0x28);
-    dprintf(ctx->avctx, AV_LOG_DEBUG, "compression id %d\n", ctx->cid);
+    cid = AV_RB32(buf + 0x28);
+    av_dlog(ctx->avctx, "compression id %d\n", cid);
 
-    if (dnxhd_init_vlc(ctx, ctx->cid) < 0)
+    if (dnxhd_init_vlc(ctx, cid) < 0)
         return -1;
 
-    if (buf_size < ctx->cid_table->frame_size) {
+    if (buf_size < ctx->cid_table->coding_unit_size) {
         av_log(ctx->avctx, AV_LOG_ERROR, "incorrect frame size\n");
         return -1;
     }
@@ -178,15 +155,20 @@ static int dnxhd_decode_header(DNXHDContext *ctx, uint8_t *buf, int buf_size)
     ctx->mb_width = ctx->width>>4;
     ctx->mb_height = buf[0x16d];
 
-    if (ctx->mb_height > 68) {
-        av_log(ctx->avctx, AV_LOG_ERROR, "mb height too big\n");
+    av_dlog(ctx->avctx, "mb width %d, mb height %d\n", ctx->mb_width, ctx->mb_height);
+
+    if ((ctx->height+15)>>4 == ctx->mb_height && ctx->picture.interlaced_frame)
+        ctx->height <<= 1;
+
+    if (ctx->mb_height > 68 ||
+        (ctx->mb_height<<ctx->picture.interlaced_frame) > (ctx->height+15)>>4) {
+        av_log(ctx->avctx, AV_LOG_ERROR, "mb height too big: %d\n", ctx->mb_height);
         return -1;
     }
 
-    dprintf(ctx->avctx, AV_LOG_DEBUG, "mb width %d, mb height %d\n", ctx->mb_width, ctx->mb_height);
     for (i = 0; i < ctx->mb_height; i++) {
         ctx->mb_scan_index[i] = AV_RB32(buf + 0x170 + (i<<2));
-        dprintf(ctx->avctx, AV_LOG_DEBUG, "mb scan index %d\n", ctx->mb_scan_index[i]);
+        av_dlog(ctx->avctx, "mb scan index %d\n", ctx->mb_scan_index[i]);
         if (buf_size < ctx->mb_scan_index[i] + 0x280) {
             av_log(ctx->avctx, AV_LOG_ERROR, "invalid mb scan index\n");
             return -1;
@@ -196,113 +178,154 @@ static int dnxhd_decode_header(DNXHDContext *ctx, uint8_t *buf, int buf_size)
     return 0;
 }
 
-static int dnxhd_decode_dc(DNXHDContext *ctx)
-{
-    int len;
-
-    len = get_vlc2(&ctx->gb, ctx->dc_vlc.table, DNXHD_DC_VLC_BITS, 1);
-    return len ? get_xbits(&ctx->gb, len) : 0;
-}
-
-static void dnxhd_decode_dct_block(DNXHDContext *ctx, DCTELEM *block, int n, int qscale)
+static av_always_inline void dnxhd_decode_dct_block(DNXHDContext *ctx,
+                                                    DCTELEM *block, int n,
+                                                    int qscale,
+                                                    int index_bits,
+                                                    int level_bias,
+                                                    int level_shift)
 {
-    int i, j, index, index2;
+    int i, j, index1, index2, len;
     int level, component, sign;
-    const uint8_t *weigth_matrix;
+    const uint8_t *weight_matrix;
+    OPEN_READER(bs, &ctx->gb);
 
     if (n&2) {
         component = 1 + (n&1);
-        weigth_matrix = ctx->chroma_weigth;
+        weight_matrix = ctx->cid_table->chroma_weight;
     } else {
         component = 0;
-        weigth_matrix = ctx->luma_weigth;
+        weight_matrix = ctx->cid_table->luma_weight;
     }
 
-    ctx->last_dc[component] += dnxhd_decode_dc(ctx);
+    UPDATE_CACHE(bs, &ctx->gb);
+    GET_VLC(len, bs, &ctx->gb, ctx->dc_vlc.table, DNXHD_DC_VLC_BITS, 1);
+    if (len) {
+        level = GET_CACHE(bs, &ctx->gb);
+        LAST_SKIP_BITS(bs, &ctx->gb, len);
+        sign  = ~level >> 31;
+        level = (NEG_USR32(sign ^ level, len) ^ sign) - sign;
+        ctx->last_dc[component] += level;
+    }
     block[0] = ctx->last_dc[component];
     //av_log(ctx->avctx, AV_LOG_DEBUG, "dc %d\n", block[0]);
+
     for (i = 1; ; i++) {
-        index = get_vlc2(&ctx->gb, ctx->ac_vlc.table, DNXHD_VLC_BITS, 2);
-        //av_log(ctx->avctx, AV_LOG_DEBUG, "index %d\n", index);
-        level = ctx->ac_level[index];
+        UPDATE_CACHE(bs, &ctx->gb);
+        GET_VLC(index1, bs, &ctx->gb, ctx->ac_vlc.table,
+                DNXHD_VLC_BITS, 2);
+        //av_log(ctx->avctx, AV_LOG_DEBUG, "index %d\n", index1);
+        level = ctx->cid_table->ac_level[index1];
         if (!level) { /* EOB */
             //av_log(ctx->avctx, AV_LOG_DEBUG, "EOB\n");
-            return;
+            break;
         }
-        sign = get_sbits(&ctx->gb, 1);
 
-        if (ctx->ac_index_flag[index]) {
-            level += get_bits(&ctx->gb, ctx->index_bits)<<6;
-        }
+        sign = SHOW_SBITS(bs, &ctx->gb, 1);
+        SKIP_BITS(bs, &ctx->gb, 1);
 
-        if (ctx->ac_run_flag[index]) {
-            index2 = get_vlc2(&ctx->gb, ctx->run_vlc.table, DNXHD_VLC_BITS, 2);
-            i += ctx->run[index2];
+        if (ctx->cid_table->ac_index_flag[index1]) {
+            level += SHOW_UBITS(bs, &ctx->gb, index_bits) << 6;
+            SKIP_BITS(bs, &ctx->gb, index_bits);
         }
 
-        j = ctx->scantable.permutated[i];
-        //av_log(ctx->avctx, AV_LOG_DEBUG, "j %d\n", j);
-        //av_log(ctx->avctx, AV_LOG_DEBUG, "level %d, weigth %d\n", level, weigth_matrix[i]);
-        level = (2*level+1) * qscale * weigth_matrix[i];
-        if (weigth_matrix[i] != 32) // FIXME 10bit
-            level += 32;
-        level >>= 6;
-        level = (level^sign) - sign;
+        if (ctx->cid_table->ac_run_flag[index1]) {
+            UPDATE_CACHE(bs, &ctx->gb);
+            GET_VLC(index2, bs, &ctx->gb, ctx->run_vlc.table,
+                    DNXHD_VLC_BITS, 2);
+            i += ctx->cid_table->run[index2];
+        }
 
         if (i > 63) {
             av_log(ctx->avctx, AV_LOG_ERROR, "ac tex damaged %d, %d\n", n, i);
-            return;
+            break;
         }
 
+        j = ctx->scantable.permutated[i];
+        //av_log(ctx->avctx, AV_LOG_DEBUG, "j %d\n", j);
+        //av_log(ctx->avctx, AV_LOG_DEBUG, "level %d, weight %d\n", level, weight_matrix[i]);
+        level = (2*level+1) * qscale * weight_matrix[i];
+        if (level_bias < 32 || weight_matrix[i] != level_bias)
+            level += level_bias;
+        level >>= level_shift;
+
         //av_log(NULL, AV_LOG_DEBUG, "i %d, j %d, end level %d\n", i, j, level);
-        block[j] = level;
+        block[j] = (level^sign) - sign;
     }
+
+    CLOSE_READER(bs, &ctx->gb);
+}
+
+static void dnxhd_decode_dct_block_8(DNXHDContext *ctx, DCTELEM *block,
+                                     int n, int qscale)
+{
+    dnxhd_decode_dct_block(ctx, block, n, qscale, 4, 32, 6);
+}
+
+static void dnxhd_decode_dct_block_10(DNXHDContext *ctx, DCTELEM *block,
+                                      int n, int qscale)
+{
+    dnxhd_decode_dct_block(ctx, block, n, qscale, 6, 8, 4);
 }
 
 static int dnxhd_decode_macroblock(DNXHDContext *ctx, int x, int y)
 {
+    int shift1 = ctx->bit_depth == 10;
     int dct_linesize_luma   = ctx->picture.linesize[0];
     int dct_linesize_chroma = ctx->picture.linesize[1];
     uint8_t *dest_y, *dest_u, *dest_v;
-    int dct_offset;
+    int dct_y_offset, dct_x_offset;
     int qscale, i;
 
-    ctx->dsp.clear_blocks(ctx->blocks[0]);
-    ctx->dsp.clear_blocks(ctx->blocks[2]); // FIXME change clear blocks to take block amount
-
     qscale = get_bits(&ctx->gb, 11);
     skip_bits1(&ctx->gb);
     //av_log(ctx->avctx, AV_LOG_DEBUG, "qscale %d\n", qscale);
 
     for (i = 0; i < 8; i++) {
-        dnxhd_decode_dct_block(ctx, ctx->blocks[i], i, qscale);
+        ctx->dsp.clear_block(ctx->blocks[i]);
+        ctx->decode_dct_block(ctx, ctx->blocks[i], i, qscale);
     }
-    dest_y = ctx->picture.data[0] + ((y * dct_linesize_luma)   << 4) + (x << 4);
-    dest_u = ctx->picture.data[1] + ((y * dct_linesize_chroma) << 4) + (x << 3);
-    dest_v = ctx->picture.data[2] + ((y * dct_linesize_chroma) << 4) + (x << 3);
 
-    dct_offset = dct_linesize_luma << 3;
-    ctx->dsp.idct_put(dest_y,                  dct_linesize_luma, ctx->blocks[0]);
-    ctx->dsp.idct_put(dest_y + 8,              dct_linesize_luma, ctx->blocks[1]);
-    ctx->dsp.idct_put(dest_y + dct_offset,     dct_linesize_luma, ctx->blocks[4]);
-    ctx->dsp.idct_put(dest_y + dct_offset + 8, dct_linesize_luma, ctx->blocks[5]);
+    if (ctx->picture.interlaced_frame) {
+        dct_linesize_luma   <<= 1;
+        dct_linesize_chroma <<= 1;
+    }
+
+    dest_y = ctx->picture.data[0] + ((y * dct_linesize_luma)   << 4) + (x << (4 + shift1));
+    dest_u = ctx->picture.data[1] + ((y * dct_linesize_chroma) << 4) + (x << (3 + shift1));
+    dest_v = ctx->picture.data[2] + ((y * dct_linesize_chroma) << 4) + (x << (3 + shift1));
+
+    if (ctx->cur_field) {
+        dest_y += ctx->picture.linesize[0];
+        dest_u += ctx->picture.linesize[1];
+        dest_v += ctx->picture.linesize[2];
+    }
+
+    dct_y_offset = dct_linesize_luma << 3;
+    dct_x_offset = 8 << shift1;
+    ctx->dsp.idct_put(dest_y,                               dct_linesize_luma, ctx->blocks[0]);
+    ctx->dsp.idct_put(dest_y + dct_x_offset,                dct_linesize_luma, ctx->blocks[1]);
+    ctx->dsp.idct_put(dest_y + dct_y_offset,                dct_linesize_luma, ctx->blocks[4]);
+    ctx->dsp.idct_put(dest_y + dct_y_offset + dct_x_offset, dct_linesize_luma, ctx->blocks[5]);
 
     if (!(ctx->avctx->flags & CODEC_FLAG_GRAY)) {
-        dct_offset = dct_linesize_chroma << 3;
-        ctx->dsp.idct_put(dest_u,              dct_linesize_chroma, ctx->blocks[2]);
-        ctx->dsp.idct_put(dest_v,              dct_linesize_chroma, ctx->blocks[3]);
-        ctx->dsp.idct_put(dest_u + dct_offset, dct_linesize_chroma, ctx->blocks[6]);
-        ctx->dsp.idct_put(dest_v + dct_offset, dct_linesize_chroma, ctx->blocks[7]);
+        dct_y_offset = dct_linesize_chroma << 3;
+        ctx->dsp.idct_put(dest_u,                dct_linesize_chroma, ctx->blocks[2]);
+        ctx->dsp.idct_put(dest_v,                dct_linesize_chroma, ctx->blocks[3]);
+        ctx->dsp.idct_put(dest_u + dct_y_offset, dct_linesize_chroma, ctx->blocks[6]);
+        ctx->dsp.idct_put(dest_v + dct_y_offset, dct_linesize_chroma, ctx->blocks[7]);
     }
 
     return 0;
 }
 
-static int dnxhd_decode_macroblocks(DNXHDContext *ctx, uint8_t *buf, int buf_size)
+static int dnxhd_decode_macroblocks(DNXHDContext *ctx, const uint8_t *buf, int buf_size)
 {
     int x, y;
     for (y = 0; y < ctx->mb_height; y++) {
-        memset(ctx->last_dc, 4, sizeof(ctx->last_dc)); // 4 for levels +128
+        ctx->last_dc[0] =
+        ctx->last_dc[1] =
+        ctx->last_dc[2] = 1 << (ctx->bit_depth + 2); // for levels +2^(bitdepth-1)
         init_get_bits(&ctx->gb, buf + ctx->mb_scan_index[y], (buf_size - ctx->mb_scan_index[y]) << 3);
         for (x = 0; x < ctx->mb_width; x++) {
             //START_TIMER;
@@ -314,55 +337,74 @@ static int dnxhd_decode_macroblocks(DNXHDContext *ctx, uint8_t *buf, int buf_siz
 }
 
 static int dnxhd_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
-                              uint8_t *buf, int buf_size)
+                              AVPacket *avpkt)
 {
+    const uint8_t *buf = avpkt->data;
+    int buf_size = avpkt->size;
     DNXHDContext *ctx = avctx->priv_data;
     AVFrame *picture = data;
+    int first_field = 1;
 
-    dprintf(avctx, AV_LOG_DEBUG, "frame size %d\n", buf_size);
+    av_dlog(avctx, "frame size %d\n", buf_size);
 
-    if (dnxhd_decode_header(ctx, buf, buf_size) < 0)
+ decode_coding_unit:
+    if (dnxhd_decode_header(ctx, buf, buf_size, first_field) < 0)
         return -1;
 
-    avctx->pix_fmt = PIX_FMT_YUV422P;
-    if (avcodec_check_dimensions(avctx, ctx->width, ctx->height))
+    if ((avctx->width || avctx->height) &&
+        (ctx->width != avctx->width || ctx->height != avctx->height)) {
+        av_log(avctx, AV_LOG_WARNING, "frame size changed: %dx%d -> %dx%d\n",
+               avctx->width, avctx->height, ctx->width, ctx->height);
+        first_field = 1;
+    }
+
+    if (av_image_check_size(ctx->width, ctx->height, 0, avctx))
         return -1;
     avcodec_set_dimensions(avctx, ctx->width, ctx->height);
 
-    if (ctx->picture.data[0])
-        avctx->release_buffer(avctx, &ctx->picture);
-    if (avctx->get_buffer(avctx, &ctx->picture) < 0) {
-        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
-        return -1;
+    if (first_field) {
+        if (ctx->picture.data[0])
+            avctx->release_buffer(avctx, &ctx->picture);
+        if (avctx->get_buffer(avctx, &ctx->picture) < 0) {
+            av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+            return -1;
+        }
     }
 
     dnxhd_decode_macroblocks(ctx, buf + 0x280, buf_size - 0x280);
 
+    if (first_field && ctx->picture.interlaced_frame) {
+        buf      += ctx->cid_table->coding_unit_size;
+        buf_size -= ctx->cid_table->coding_unit_size;
+        first_field = 0;
+        goto decode_coding_unit;
+    }
+
     *picture = ctx->picture;
     *data_size = sizeof(AVPicture);
-    return 0;
+    return buf_size;
 }
 
-static int dnxhd_decode_close(AVCodecContext *avctx)
+static av_cold int dnxhd_decode_close(AVCodecContext *avctx)
 {
     DNXHDContext *ctx = avctx->priv_data;
 
-    if(ctx->picture.data[0])
+    if (ctx->picture.data[0])
         avctx->release_buffer(avctx, &ctx->picture);
-    free_vlc(&ctx->ac_vlc);
-    free_vlc(&ctx->dc_vlc);
-    free_vlc(&ctx->run_vlc);
+    ff_free_vlc(&ctx->ac_vlc);
+    ff_free_vlc(&ctx->dc_vlc);
+    ff_free_vlc(&ctx->run_vlc);
     return 0;
 }
 
-AVCodec dnxhd_decoder = {
-    "dnxhd",
-    CODEC_TYPE_VIDEO,
-    CODEC_ID_DNXHD,
-    sizeof(DNXHDContext),
-    dnxhd_decode_init,
-    NULL,
-    dnxhd_decode_close,
-    dnxhd_decode_frame,
-    CODEC_CAP_DR1,
+AVCodec ff_dnxhd_decoder = {
+    .name           = "dnxhd",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = CODEC_ID_DNXHD,
+    .priv_data_size = sizeof(DNXHDContext),
+    .init           = dnxhd_decode_init,
+    .close          = dnxhd_decode_close,
+    .decode         = dnxhd_decode_frame,
+    .capabilities   = CODEC_CAP_DR1,
+    .long_name      = NULL_IF_CONFIG_SMALL("VC3/DNxHD"),
 };