roqvideo: convert to bytestream2 API.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
(cherry picked from commit cdf15771621bce7959b3e53b21426c5ba747e17b)

Signed-off-by: Reinhard Tartler <siretart@tauware.de>

2 files changed, 37 insertions, 36 deletions

diff --git a/libavcodec/roqvideo.h b/libavcodec/roqvideo.h
index a1ff10af7d..4e6e5bb7db 100644
--- a/libavcodec/roqvideo.h
+++ b/libavcodec/roqvideo.h
@@ -24,6 +24,7 @@
 
 #include "libavutil/lfg.h"
 #include "avcodec.h"
+#include "bytestream.h"
 #include "dsputil.h"
 
 typedef struct {
@@ -53,8 +54,7 @@ typedef struct RoqContext {
     roq_cell cb2x2[256];
     roq_qcell cb4x4[256];
 
-    const unsigned char *buf;
-    int size;
+    GetByteContext gb;
     int width, height;
 
     /* Encoder only data */
diff --git a/libavcodec/roqvideodec.c b/libavcodec/roqvideodec.c
index 527ba51c99..0bf00cf380 100644
--- a/libavcodec/roqvideodec.c
+++ b/libavcodec/roqvideodec.c
@@ -38,16 +38,15 @@ static void roqvideo_decode_frame(RoqContext *ri)
     unsigned int chunk_id = 0, chunk_arg = 0;
     unsigned long chunk_size = 0;
     int i, j, k, nv1, nv2, vqflg = 0, vqflg_pos = -1;
-    int vqid, bpos, xpos, ypos, xp, yp, x, y, mx, my;
+    int vqid, xpos, ypos, xp, yp, x, y, mx, my;
     int frame_stats[2][4] = {{0},{0}};
     roq_qcell *qcell;
-    const unsigned char *buf = ri->buf;
-    const unsigned char *buf_end = ri->buf + ri->size;
+    int64_t chunk_start;
 
-    while (buf < buf_end) {
-        chunk_id = bytestream_get_le16(&buf);
-        chunk_size = bytestream_get_le32(&buf);
-        chunk_arg = bytestream_get_le16(&buf);
+    while (bytestream2_get_bytes_left(&ri->gb) > 0) {
+        chunk_id = bytestream2_get_le16(&ri->gb);
+        chunk_size = bytestream2_get_le32(&ri->gb);
+        chunk_arg = bytestream2_get_le16(&ri->gb);
 
         if(chunk_id == RoQ_QUAD_VQ)
             break;
@@ -57,25 +56,26 @@ static void roqvideo_decode_frame(RoqContext *ri)
             if((nv2 = chunk_arg & 0xff) == 0 && nv1 * 6 < chunk_size)
                 nv2 = 256;
             for(i = 0; i < nv1; i++) {
-                ri->cb2x2[i].y[0] = *buf++;
-                ri->cb2x2[i].y[1] = *buf++;
-                ri->cb2x2[i].y[2] = *buf++;
-                ri->cb2x2[i].y[3] = *buf++;
-                ri->cb2x2[i].u = *buf++;
-                ri->cb2x2[i].v = *buf++;
+                ri->cb2x2[i].y[0] = bytestream2_get_byte(&ri->gb);
+                ri->cb2x2[i].y[1] = bytestream2_get_byte(&ri->gb);
+                ri->cb2x2[i].y[2] = bytestream2_get_byte(&ri->gb);
+                ri->cb2x2[i].y[3] = bytestream2_get_byte(&ri->gb);
+                ri->cb2x2[i].u = bytestream2_get_byte(&ri->gb);
+                ri->cb2x2[i].v = bytestream2_get_byte(&ri->gb);
             }
             for(i = 0; i < nv2; i++)
                 for(j = 0; j < 4; j++)
-                    ri->cb4x4[i].idx[j] = *buf++;
+                    ri->cb4x4[i].idx[j] = bytestream2_get_byte(&ri->gb);
         }
     }
 
-    bpos = xpos = ypos = 0;
-    while(bpos < chunk_size) {
+    chunk_start = bytestream2_tell(&ri->gb);
+    xpos = ypos = 0;
+    while (bytestream2_tell(&ri->gb) < chunk_start + chunk_size) {
         for (yp = ypos; yp < ypos + 16; yp += 8)
             for (xp = xpos; xp < xpos + 16; xp += 8) {
                 if (vqflg_pos < 0) {
-                    vqflg = buf[bpos++]; vqflg |= (buf[bpos++] << 8);
+                    vqflg = bytestream2_get_le16(&ri->gb);
                     vqflg_pos = 7;
                 }
                 vqid = (vqflg >> (vqflg_pos * 2)) & 0x3;
@@ -85,13 +85,15 @@ static void roqvideo_decode_frame(RoqContext *ri)
                 switch(vqid) {
                 case RoQ_ID_MOT:
                     break;
-                case RoQ_ID_FCC:
-                    mx = 8 - (buf[bpos] >> 4) - ((signed char) (chunk_arg >> 8));
-                    my = 8 - (buf[bpos++] & 0xf) - ((signed char) chunk_arg);
+                case RoQ_ID_FCC: {
+                    int byte = bytestream2_get_byte(&ri->gb);
+                    mx = 8 - (byte >> 4) - ((signed char) (chunk_arg >> 8));
+                    my = 8 - (byte & 0xf) - ((signed char) chunk_arg);
                     ff_apply_motion_8x8(ri, xp, yp, mx, my);
                     break;
+                }
                 case RoQ_ID_SLD:
-                    qcell = ri->cb4x4 + buf[bpos++];
+                    qcell = ri->cb4x4 + bytestream2_get_byte(&ri->gb);
                     ff_apply_vector_4x4(ri, xp, yp, ri->cb2x2 + qcell->idx[0]);
                     ff_apply_vector_4x4(ri, xp+4, yp, ri->cb2x2 + qcell->idx[1]);
                     ff_apply_vector_4x4(ri, xp, yp+4, ri->cb2x2 + qcell->idx[2]);
@@ -104,8 +106,7 @@ static void roqvideo_decode_frame(RoqContext *ri)
                         if(k & 0x02) y += 4;
 
                         if (vqflg_pos < 0) {
-                            vqflg = buf[bpos++];
-                            vqflg |= (buf[bpos++] << 8);
+                            vqflg = bytestream2_get_le16(&ri->gb);
                             vqflg_pos = 7;
                         }
                         vqid = (vqflg >> (vqflg_pos * 2)) & 0x3;
@@ -114,24 +115,25 @@ static void roqvideo_decode_frame(RoqContext *ri)
                         switch(vqid) {
                         case RoQ_ID_MOT:
                             break;
-                        case RoQ_ID_FCC:
-                            mx = 8 - (buf[bpos] >> 4) - ((signed char) (chunk_arg >> 8));
-                            my = 8 - (buf[bpos++] & 0xf) - ((signed char) chunk_arg);
+                        case RoQ_ID_FCC: {
+                            int byte = bytestream2_get_byte(&ri->gb);
+                            mx = 8 - (byte >> 4) - ((signed char) (chunk_arg >> 8));
+                            my = 8 - (byte & 0xf) - ((signed char) chunk_arg);
                             ff_apply_motion_4x4(ri, x, y, mx, my);
                             break;
+                        }
                         case RoQ_ID_SLD:
-                            qcell = ri->cb4x4 + buf[bpos++];
+                            qcell = ri->cb4x4 + bytestream2_get_byte(&ri->gb);
                             ff_apply_vector_2x2(ri, x, y, ri->cb2x2 + qcell->idx[0]);
                             ff_apply_vector_2x2(ri, x+2, y, ri->cb2x2 + qcell->idx[1]);
                             ff_apply_vector_2x2(ri, x, y+2, ri->cb2x2 + qcell->idx[2]);
                             ff_apply_vector_2x2(ri, x+2, y+2, ri->cb2x2 + qcell->idx[3]);
                             break;
                         case RoQ_ID_CCC:
-                            ff_apply_vector_2x2(ri, x, y, ri->cb2x2 + buf[bpos]);
-                            ff_apply_vector_2x2(ri, x+2, y, ri->cb2x2 + buf[bpos+1]);
-                            ff_apply_vector_2x2(ri, x, y+2, ri->cb2x2 + buf[bpos+2]);
-                            ff_apply_vector_2x2(ri, x+2, y+2, ri->cb2x2 + buf[bpos+3]);
-                            bpos += 4;
+                            ff_apply_vector_2x2(ri, x, y, ri->cb2x2 + bytestream2_get_byte(&ri->gb));
+                            ff_apply_vector_2x2(ri, x+2, y, ri->cb2x2 + bytestream2_get_byte(&ri->gb));
+                            ff_apply_vector_2x2(ri, x, y+2, ri->cb2x2 + bytestream2_get_byte(&ri->gb));
+                            ff_apply_vector_2x2(ri, x+2, y+2, ri->cb2x2 + bytestream2_get_byte(&ri->gb));
                             break;
                         }
                     }
@@ -185,8 +187,7 @@ static int roq_decode_frame(AVCodecContext *avctx,
         av_picture_copy((AVPicture*)s->current_frame, (AVPicture*)s->last_frame,
                         avctx->pix_fmt, avctx->width, avctx->height);
 
-    s->buf = buf;
-    s->size = buf_size;
+    bytestream2_init(&s->gb, buf, buf_size);
     roqvideo_decode_frame(s);
 
     *data_size = sizeof(AVFrame);