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FFmpeg
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squashed a bunch of subtle array indexing bugs, fixed block mapping 

added more error checking, added (and enabled, for the time being) a
keyframe-only mode

Originally committed as revision 1849 to svn://svn.ffmpeg.org/ffmpeg/trunk
tags/v0.5
Mike Melanson 22 years ago
parent
85ea6b2958
commit
892fc83e88
1 changed files with 143 additions and 45 deletions
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  1. +143
    -45
      libavcodec/vp3.c

+ 143
- 45
libavcodec/vp3.c View File

@@ -225,6 +225,10 @@ typedef struct Vp3DecodeContext {
int superblock_count;
int superblock_width;
int superblock_height;
int y_superblock_width;
int y_superblock_height;
int c_superblock_width;
int c_superblock_height;
int u_superblock_start;
int v_superblock_start;
unsigned char *superblock_coding;
@@ -292,8 +296,10 @@ typedef struct Vp3DecodeContext {
* This function sets up all of the various blocks mappings:
* superblocks <-> fragments, macroblocks <-> fragments,
* superblocks <-> macroblocks
*
* Returns 0 is successful; returns 1 if *anything* went wrong.
*/
static void init_block_mapping(Vp3DecodeContext *s)
static int init_block_mapping(Vp3DecodeContext *s)
{
int i, j;
signed int hilbert_walk_y[16];
@@ -387,9 +393,10 @@ static void init_block_mapping(Vp3DecodeContext *s)
/* start of Y superblocks */
right_edge = s->fragment_width;
bottom_edge = s->fragment_height;
current_width = 0;
current_width = -1;
current_height = 0;
superblock_row_inc = 3 * s->fragment_width;
superblock_row_inc = 3 * s->fragment_width -
(s->y_superblock_width * 4 - s->fragment_width);
hilbert = hilbert_walk_y;

/* the first operation for this variable is to advance by 1 */
@@ -400,9 +407,10 @@ static void init_block_mapping(Vp3DecodeContext *s)
/* start of U superblocks */
right_edge = s->fragment_width / 2;
bottom_edge = s->fragment_height / 2;
current_width = 0;
current_width = -1;
current_height = 0;
superblock_row_inc = 3 * (s->fragment_width / 2);
superblock_row_inc = 3 * (s->fragment_width / 2) -
(s->c_superblock_width * 4 - s->fragment_width / 2);
hilbert = hilbert_walk_c;

/* the first operation for this variable is to advance by 1 */
@@ -413,9 +421,10 @@ static void init_block_mapping(Vp3DecodeContext *s)
/* start of V superblocks */
right_edge = s->fragment_width / 2;
bottom_edge = s->fragment_height / 2;
current_width = 0;
current_width = -1;
current_height = 0;
superblock_row_inc = 3 * (s->fragment_width / 2);
superblock_row_inc = 3 * (s->fragment_width / 2) -
(s->c_superblock_width * 4 - s->fragment_width / 2);
hilbert = hilbert_walk_c;

/* the first operation for this variable is to advance by 1 */
@@ -423,9 +432,9 @@ static void init_block_mapping(Vp3DecodeContext *s)

}

if (current_width >= right_edge) {
if (current_width >= right_edge - 1) {
/* reset width and move to next superblock row */
current_width = 0;
current_width = -1;
current_height += 4;

/* fragment is now at the start of a new superblock row */
@@ -435,21 +444,23 @@ static void init_block_mapping(Vp3DecodeContext *s)
/* iterate through all 16 fragments in a superblock */
for (j = 0; j < 16; j++) {
current_fragment += hilbert[j];
current_width += travel_width[j];
current_height += travel_height[j];

/* check if the fragment is in bounds */
if ((current_width <= right_edge) &&
if ((current_width < right_edge) &&
(current_height < bottom_edge)) {
s->superblock_fragments[mapping_index] = current_fragment;
debug_init(" mapping fragment %d to superblock %d, position %d\n",
s->superblock_fragments[mapping_index], i, j);
debug_init(" mapping fragment %d to superblock %d, position %d (%d/%d x %d/%d)\n",
s->superblock_fragments[mapping_index], i, j,
current_width, right_edge, current_height, bottom_edge);
} else {
s->superblock_fragments[mapping_index] = -1;
debug_init(" superblock %d, position %d has no fragment\n",
i, j);
debug_init(" superblock %d, position %d has no fragment (%d/%d x %d/%d)\n",
i, j,
current_width, right_edge, current_height, bottom_edge);
}

current_width += travel_width[j];
mapping_index++;
}
}
@@ -458,9 +469,10 @@ static void init_block_mapping(Vp3DecodeContext *s)
* all of the Y plane superblocks to build this mapping */
right_edge = s->macroblock_width;
bottom_edge = s->macroblock_height;
current_width = 0;
current_width = -1;
current_height = 0;
superblock_row_inc = s->macroblock_width;
superblock_row_inc = s->macroblock_width -
(s->y_superblock_width * 2 - s->macroblock_width);;
hilbert = hilbert_walk_mb;
mapping_index = 0;
current_macroblock = -1;
@@ -478,10 +490,11 @@ static void init_block_mapping(Vp3DecodeContext *s)
/* iterate through each potential macroblock in the superblock */
for (j = 0; j < 4; j++) {
current_macroblock += hilbert_walk_mb[j];
current_width += travel_width_mb[j];
current_height += travel_height_mb[j];

/* check if the macroblock is in bounds */
if ((current_width <= right_edge) &&
if ((current_width < right_edge) &&
(current_height < bottom_edge)) {
s->superblock_macroblocks[mapping_index] = current_macroblock;
debug_init(" mapping macroblock %d to superblock %d, position %d\n",
@@ -492,7 +505,6 @@ static void init_block_mapping(Vp3DecodeContext *s)
i, j);
}

current_width += travel_width_mb[j];
mapping_index++;
}
}
@@ -538,13 +550,13 @@ static void init_block_mapping(Vp3DecodeContext *s)
/* C planes */
c_fragment = s->u_fragment_start +
(i * s->fragment_width / 4) + (j / 2);
s->all_fragments[c_fragment].macroblock = s->macroblock_count;
s->all_fragments[c_fragment].macroblock = s->macroblock_count;
s->macroblock_fragments[mapping_index++] = c_fragment;
debug_init("%d ", c_fragment);

c_fragment = s->v_fragment_start +
(i * s->fragment_width / 4) + (j / 2);
s->all_fragments[c_fragment].macroblock = s->macroblock_count;
s->all_fragments[c_fragment].macroblock = s->macroblock_count;
s->macroblock_fragments[mapping_index++] = c_fragment;
debug_init("%d ", c_fragment);

@@ -559,6 +571,8 @@ static void init_block_mapping(Vp3DecodeContext *s)

current_fragment += s->fragment_width;
}

return 0; /* successful path out */
}

/*
@@ -1106,7 +1120,7 @@ static int get_motion_vector_fixed(GetBitContext *gb)
* This function unpacks all of the superblock/macroblock/fragment coding
* information from the bitstream.
*/
static void unpack_superblocks(Vp3DecodeContext *s, GetBitContext *gb)
static int unpack_superblocks(Vp3DecodeContext *s, GetBitContext *gb)
{
int bit = 0;
int current_superblock = 0;
@@ -1212,6 +1226,11 @@ static void unpack_superblocks(Vp3DecodeContext *s, GetBitContext *gb)

/* if the fragment is in bounds, check its coding status */
current_fragment = s->superblock_fragments[i * 16 + j];
if (current_fragment >= s->fragment_count) {
printf (" vp3:unpack_superblocks(): bad fragment number (%d >= %d)\n",
current_fragment, s->fragment_count);
return 1;
}
if (current_fragment != -1) {
if (s->superblock_coding[i] == SB_NOT_CODED) {

@@ -1286,13 +1305,15 @@ static void unpack_superblocks(Vp3DecodeContext *s, GetBitContext *gb)
s->last_coded_y_fragment,
s->first_coded_c_fragment,
s->last_coded_c_fragment);

return 0;
}

/*
* This function unpacks all the coding mode data for individual macroblocks
* from the bitstream.
*/
static void unpack_modes(Vp3DecodeContext *s, GetBitContext *gb)
static int unpack_modes(Vp3DecodeContext *s, GetBitContext *gb)
{
int i, j, k;
int scheme;
@@ -1334,6 +1355,11 @@ static void unpack_modes(Vp3DecodeContext *s, GetBitContext *gb)
if ((current_macroblock == -1) ||
(!s->macroblock_coded[current_macroblock]))
continue;
if (current_macroblock >= s->macroblock_count) {
printf (" vp3:unpack_modes(): bad macroblock number (%d >= %d)\n",
current_macroblock, s->macroblock_count);
return 1;
}

/* mode 7 means get 3 bits for each coding mode */
if (scheme == 7)
@@ -1344,6 +1370,13 @@ static void unpack_modes(Vp3DecodeContext *s, GetBitContext *gb)
for (k = 0; k < 6; k++) {
current_fragment =
s->macroblock_fragments[current_macroblock * 6 + k];
if (current_fragment == -1)
continue;
if (current_fragment >= s->fragment_count) {
printf (" vp3:unpack_modes(): bad fragment number (%d >= %d)\n",
current_fragment, s->fragment_count);
return 1;
}
if (s->all_fragments[current_fragment].coding_method !=
MODE_COPY)
s->all_fragments[current_fragment].coding_method =
@@ -1355,6 +1388,8 @@ static void unpack_modes(Vp3DecodeContext *s, GetBitContext *gb)
}
}
}

return 0;
}

/*
@@ -1410,7 +1445,7 @@ static inline int adjust_vector(int *x, int *y, int c_plane)
* This function unpacks all the motion vectors for the individual
* macroblocks from the bitstream.
*/
static void unpack_vectors(Vp3DecodeContext *s, GetBitContext *gb)
static int unpack_vectors(Vp3DecodeContext *s, GetBitContext *gb)
{
int i, j, k;
int coding_mode;
@@ -1448,8 +1483,18 @@ static void unpack_vectors(Vp3DecodeContext *s, GetBitContext *gb)
if ((current_macroblock == -1) ||
(!s->macroblock_coded[current_macroblock]))
continue;
if (current_macroblock >= s->macroblock_count) {
printf (" vp3:unpack_vectors(): bad macroblock number (%d >= %d)\n",
current_macroblock, s->macroblock_count);
return 1;
}

current_fragment = s->macroblock_fragments[current_macroblock * 6];
if (current_fragment >= s->fragment_count) {
printf (" vp3:unpack_vectors(): bad fragment number (%d >= %d\n",
current_fragment, s->fragment_count);
return 1;
}
switch (s->all_fragments[current_fragment].coding_method) {

case MODE_INTER_PLUS_MV:
@@ -1559,6 +1604,13 @@ static void unpack_vectors(Vp3DecodeContext *s, GetBitContext *gb)
for (k = 0; k < 6; k++) {
current_fragment =
s->macroblock_fragments[current_macroblock * 6 + k];
if (current_fragment == -1)
continue;
if (current_fragment >= s->fragment_count) {
printf (" vp3:unpack_vectors(): bad fragment number (%d >= %d)\n",
current_fragment, s->fragment_count);
return 1;
}
s->all_fragments[current_fragment].motion_halfpel_index =
adjust_vector(&motion_x[k], &motion_y[k],
((k == 4) || (k == 5)));
@@ -1571,6 +1623,8 @@ static void unpack_vectors(Vp3DecodeContext *s, GetBitContext *gb)
}
}
}

return 0;
}

/*
@@ -1632,7 +1686,7 @@ static int unpack_vlcs(Vp3DecodeContext *s, GetBitContext *gb,
* This function unpacks all of the DCT coefficient data from the
* bitstream.
*/
static void unpack_dct_coeffs(Vp3DecodeContext *s, GetBitContext *gb)
static int unpack_dct_coeffs(Vp3DecodeContext *s, GetBitContext *gb)
{
int i;
int dc_y_table;
@@ -1716,6 +1770,8 @@ static void unpack_dct_coeffs(Vp3DecodeContext *s, GetBitContext *gb)
residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_4[ac_c_table], i,
s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);
}

return 0;
}

/*
@@ -2072,6 +2128,7 @@ static void render_fragments(Vp3DecodeContext *s,
(motion_source > lower_motion_limit)) {
// printf (" vp3: help! motion source (%d) out of range (%d..%d)\n",
// motion_source, upper_motion_limit, lower_motion_limit);
continue;
}

/* first, take care of copying a block from either the
@@ -2210,6 +2267,10 @@ static int vp3_decode_init(AVCodecContext *avctx)
{
Vp3DecodeContext *s = avctx->priv_data;
int i;
int c_width;
int c_height;
int y_superblock_count;
int c_superblock_count;

s->avctx = avctx;
s->width = avctx->width;
@@ -2222,11 +2283,20 @@ static int vp3_decode_init(AVCodecContext *avctx)
* in the first frame decode */
s->quality_index = -1;

s->superblock_width = (s->width + 31) / 32;
s->superblock_height = (s->height + 31) / 32;
s->superblock_count = s->superblock_width * s->superblock_height * 3 / 2;
s->u_superblock_start = s->superblock_width * s->superblock_height;
s->v_superblock_start = s->superblock_width * s->superblock_height * 5 / 4;
s->y_superblock_width = (s->width + 31) / 32;
s->y_superblock_height = (s->height + 31) / 32;
y_superblock_count = s->y_superblock_width * s->y_superblock_height;

/* work out the dimensions for the C planes */
c_width = s->width / 2;
c_height = s->height / 2;
s->c_superblock_width = (c_width + 31) / 32;
s->c_superblock_height = (c_height + 31) / 32;
c_superblock_count = s->c_superblock_width * s->c_superblock_height;

s->superblock_count = y_superblock_count + (c_superblock_count * 2);
s->u_superblock_start = y_superblock_count;
s->v_superblock_start = s->u_superblock_start + c_superblock_count;
s->superblock_coding = av_malloc(s->superblock_count);

s->macroblock_width = (s->width + 15) / 16;
@@ -2241,9 +2311,14 @@ static int vp3_decode_init(AVCodecContext *avctx)
s->u_fragment_start = s->fragment_width * s->fragment_height;
s->v_fragment_start = s->fragment_width * s->fragment_height * 5 / 4;

debug_init(" width: %d x %d\n", s->width, s->height);
debug_init(" superblocks: %d x %d, %d total\n",
s->superblock_width, s->superblock_height, s->superblock_count);
debug_init(" Y plane: %d x %d\n", s->width, s->height);
debug_init(" C plane: %d x %d\n", c_width, c_height);
debug_init(" Y superblocks: %d x %d, %d total\n",
s->y_superblock_width, s->y_superblock_height, y_superblock_count);
debug_init(" C superblocks: %d x %d, %d total\n",
s->c_superblock_width, s->c_superblock_height, c_superblock_count);
debug_init(" total superblocks = %d, U starts @ %d, V starts @ %d\n",
s->superblock_count, s->u_superblock_start, s->v_superblock_start);
debug_init(" macroblocks: %d x %d, %d total\n",
s->macroblock_width, s->macroblock_height, s->macroblock_count);
debug_init(" %d fragments, %d x %d, u starts @ %d, v starts @ %d\n",
@@ -2333,12 +2408,10 @@ static int vp3_decode_frame(AVCodecContext *avctx,
counter++;

if (s->keyframe) {
/* release the previous golden frame and get a new one */
if (s->golden_frame.data[0])
if ((s->golden_frame.data[0]) &&
(s->last_frame.data[0] == s->golden_frame.data[0]))
avctx->release_buffer(avctx, &s->golden_frame);

/* last frame, if allocated, is hereby invalidated */
if (s->last_frame.data[0])
else if (s->last_frame.data[0])
avctx->release_buffer(avctx, &s->last_frame);

s->golden_frame.reference = 0;
@@ -2374,10 +2447,28 @@ static int vp3_decode_frame(AVCodecContext *avctx,

init_frame(s, &gb);

unpack_superblocks(s, &gb);
unpack_modes(s, &gb);
unpack_vectors(s, &gb);
unpack_dct_coeffs(s, &gb);
#define KEYFRAMES_ONLY 1
#if KEYFRAMES_ONLY
if (!s->keyframe) {

memcpy(s->current_frame.data[0], s->golden_frame.data[0],
s->current_frame.linesize[0] * s->height);
memcpy(s->current_frame.data[1], s->golden_frame.data[1],
s->current_frame.linesize[1] * s->height / 2);
memcpy(s->current_frame.data[2], s->golden_frame.data[2],
s->current_frame.linesize[2] * s->height / 2);

} else {
#endif

if (unpack_superblocks(s, &gb) ||
unpack_modes(s, &gb) ||
unpack_vectors(s, &gb) ||
unpack_dct_coeffs(s, &gb)) {

printf(" vp3: could not decode frame\n");
return -1;
}

reverse_dc_prediction(s, 0, s->fragment_width, s->fragment_height);
reverse_dc_prediction(s, s->u_fragment_start,
@@ -2389,6 +2480,10 @@ static int vp3_decode_frame(AVCodecContext *avctx,
render_fragments(s, s->u_fragment_start, s->width / 2, s->height / 2, 1);
render_fragments(s, s->v_fragment_start, s->width / 2, s->height / 2, 2);

#if KEYFRAMES_ONLY
}
#endif

*data_size=sizeof(AVFrame);
*(AVFrame*)data= s->current_frame;

@@ -2419,9 +2514,12 @@ static int vp3_decode_end(AVCodecContext *avctx)
av_free(s->macroblock_coded);

/* release all frames */
avctx->release_buffer(avctx, &s->golden_frame);
avctx->release_buffer(avctx, &s->last_frame);
avctx->release_buffer(avctx, &s->current_frame);
if (s->golden_frame.data[0])
avctx->release_buffer(avctx, &s->golden_frame);
if (s->last_frame.data[0])
avctx->release_buffer(avctx, &s->last_frame);
/* no need to release the current_frame since it will always be pointing
* to the same frame as either the golden or last frame */

return 0;
}


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