avcodec/exr: refactor GetByteContext usage

pull/371/head
Paul B Mahol 4 years ago
parent 3ea660c78a
commit f5dde8089d
  1. 131
      libavcodec/exr.c

@ -1276,16 +1276,18 @@ static int decode_block(AVCodecContext *avctx, void *tdata,
static void skip_header_chunk(EXRContext *s)
{
while (bytestream2_get_bytes_left(&s->gb) > 0) {
if (!bytestream2_peek_byte(&s->gb))
GetByteContext *gb = &s->gb;
while (bytestream2_get_bytes_left(gb) > 0) {
if (!bytestream2_peek_byte(gb))
break;
// Process unknown variables
for (int i = 0; i < 2; i++) // value_name and value_type
while (bytestream2_get_byte(&s->gb) != 0);
while (bytestream2_get_byte(gb) != 0);
// Skip variable length
bytestream2_skip(&s->gb, bytestream2_get_le32(&s->gb));
bytestream2_skip(gb, bytestream2_get_le32(gb));
}
}
@ -1306,21 +1308,22 @@ static int check_header_variable(EXRContext *s,
const char *value_type,
unsigned int minimum_length)
{
GetByteContext *gb = &s->gb;
int var_size = -1;
if (bytestream2_get_bytes_left(&s->gb) >= minimum_length &&
!strcmp(s->gb.buffer, value_name)) {
if (bytestream2_get_bytes_left(gb) >= minimum_length &&
!strcmp(gb->buffer, value_name)) {
// found value_name, jump to value_type (null terminated strings)
s->gb.buffer += strlen(value_name) + 1;
if (!strcmp(s->gb.buffer, value_type)) {
s->gb.buffer += strlen(value_type) + 1;
var_size = bytestream2_get_le32(&s->gb);
gb->buffer += strlen(value_name) + 1;
if (!strcmp(gb->buffer, value_type)) {
gb->buffer += strlen(value_type) + 1;
var_size = bytestream2_get_le32(gb);
// don't go read past boundaries
if (var_size > bytestream2_get_bytes_left(&s->gb))
if (var_size > bytestream2_get_bytes_left(gb))
var_size = 0;
} else {
// value_type not found, reset the buffer
s->gb.buffer -= strlen(value_name) + 1;
gb->buffer -= strlen(value_name) + 1;
av_log(s->avctx, AV_LOG_WARNING,
"Unknown data type %s for header variable %s.\n",
value_type, value_name);
@ -1333,6 +1336,7 @@ static int check_header_variable(EXRContext *s,
static int decode_header(EXRContext *s, AVFrame *frame)
{
AVDictionary *metadata = NULL;
GetByteContext *gb = &s->gb;
int magic_number, version, i, flags;
int layer_match = 0;
int ret;
@ -1361,12 +1365,12 @@ static int decode_header(EXRContext *s, AVFrame *frame)
s->is_luma = 0;
s->current_part = 0;
if (bytestream2_get_bytes_left(&s->gb) < 10) {
if (bytestream2_get_bytes_left(gb) < 10) {
av_log(s->avctx, AV_LOG_ERROR, "Header too short to parse.\n");
return AVERROR_INVALIDDATA;
}
magic_number = bytestream2_get_le32(&s->gb);
magic_number = bytestream2_get_le32(gb);
if (magic_number != 20000630) {
/* As per documentation of OpenEXR, it is supposed to be
* int 20000630 little-endian */
@ -1374,13 +1378,13 @@ static int decode_header(EXRContext *s, AVFrame *frame)
return AVERROR_INVALIDDATA;
}
version = bytestream2_get_byte(&s->gb);
version = bytestream2_get_byte(gb);
if (version != 2) {
avpriv_report_missing_feature(s->avctx, "Version %d", version);
return AVERROR_PATCHWELCOME;
}
flags = bytestream2_get_le24(&s->gb);
flags = bytestream2_get_le24(gb);
if (flags & 0x02)
s->is_tile = 1;
@ -1392,38 +1396,38 @@ static int decode_header(EXRContext *s, AVFrame *frame)
}
// Parse the header
while (bytestream2_get_bytes_left(&s->gb) > 0) {
while (bytestream2_get_bytes_left(gb) > 0) {
int var_size;
while (s->is_multipart && s->current_part < s->selected_part &&
bytestream2_get_bytes_left(&s->gb) > 0) {
if (bytestream2_peek_byte(&s->gb)) {
bytestream2_get_bytes_left(gb) > 0) {
if (bytestream2_peek_byte(gb)) {
skip_header_chunk(s);
} else {
bytestream2_skip(&s->gb, 1);
if (!bytestream2_peek_byte(&s->gb))
bytestream2_skip(gb, 1);
if (!bytestream2_peek_byte(gb))
break;
}
bytestream2_skip(&s->gb, 1);
bytestream2_skip(gb, 1);
s->current_part++;
}
if (!bytestream2_peek_byte(&s->gb)) {
if (!bytestream2_peek_byte(gb)) {
if (!s->is_multipart)
break;
bytestream2_skip(&s->gb, 1);
bytestream2_skip(gb, 1);
if (s->current_part == s->selected_part) {
while (bytestream2_get_bytes_left(&s->gb) > 0) {
if (bytestream2_peek_byte(&s->gb)) {
while (bytestream2_get_bytes_left(gb) > 0) {
if (bytestream2_peek_byte(gb)) {
skip_header_chunk(s);
} else {
bytestream2_skip(&s->gb, 1);
if (!bytestream2_peek_byte(&s->gb))
bytestream2_skip(gb, 1);
if (!bytestream2_peek_byte(gb))
break;
}
}
}
if (!bytestream2_peek_byte(&s->gb))
if (!bytestream2_peek_byte(gb))
break;
s->current_part++;
}
@ -1436,7 +1440,7 @@ static int decode_header(EXRContext *s, AVFrame *frame)
goto fail;
}
bytestream2_init(&ch_gb, s->gb.buffer, var_size);
bytestream2_init(&ch_gb, gb->buffer, var_size);
while (bytestream2_get_bytes_left(&ch_gb) >= 19) {
EXRChannel *channel;
@ -1573,7 +1577,7 @@ static int decode_header(EXRContext *s, AVFrame *frame)
}
// skip one last byte and update main gb
s->gb.buffer = ch_gb.buffer + 1;
gb->buffer = ch_gb.buffer + 1;
continue;
} else if ((var_size = check_header_variable(s, "dataWindow", "box2i",
31)) >= 0) {
@ -1583,10 +1587,10 @@ static int decode_header(EXRContext *s, AVFrame *frame)
goto fail;
}
xmin = bytestream2_get_le32(&s->gb);
ymin = bytestream2_get_le32(&s->gb);
xmax = bytestream2_get_le32(&s->gb);
ymax = bytestream2_get_le32(&s->gb);
xmin = bytestream2_get_le32(gb);
ymin = bytestream2_get_le32(gb);
xmax = bytestream2_get_le32(gb);
ymax = bytestream2_get_le32(gb);
if (xmin > xmax || ymin > ymax ||
(unsigned)xmax - xmin >= INT_MAX ||
@ -1611,10 +1615,10 @@ static int decode_header(EXRContext *s, AVFrame *frame)
goto fail;
}
sx = bytestream2_get_le32(&s->gb);
sy = bytestream2_get_le32(&s->gb);
dx = bytestream2_get_le32(&s->gb);
dy = bytestream2_get_le32(&s->gb);
sx = bytestream2_get_le32(gb);
sy = bytestream2_get_le32(gb);
dx = bytestream2_get_le32(gb);
dy = bytestream2_get_le32(gb);
s->w = dx - sx + 1;
s->h = dy - sy + 1;
@ -1628,7 +1632,7 @@ static int decode_header(EXRContext *s, AVFrame *frame)
goto fail;
}
line_order = bytestream2_get_byte(&s->gb);
line_order = bytestream2_get_byte(gb);
av_log(s->avctx, AV_LOG_DEBUG, "line order: %d.\n", line_order);
if (line_order > 2) {
av_log(s->avctx, AV_LOG_ERROR, "Unknown line order.\n");
@ -1644,7 +1648,7 @@ static int decode_header(EXRContext *s, AVFrame *frame)
goto fail;
}
s->sar = bytestream2_get_le32(&s->gb);
s->sar = bytestream2_get_le32(gb);
continue;
} else if ((var_size = check_header_variable(s, "compression",
@ -1655,9 +1659,9 @@ static int decode_header(EXRContext *s, AVFrame *frame)
}
if (s->compression == EXR_UNKN)
s->compression = bytestream2_get_byte(&s->gb);
s->compression = bytestream2_get_byte(gb);
else {
bytestream2_skip(&s->gb, 1);
bytestream2_skip(gb, 1);
av_log(s->avctx, AV_LOG_WARNING,
"Found more than one compression attribute.\n");
}
@ -1671,10 +1675,10 @@ static int decode_header(EXRContext *s, AVFrame *frame)
av_log(s->avctx, AV_LOG_WARNING,
"Found tile attribute and scanline flags. Exr will be interpreted as scanline.\n");
s->tile_attr.xSize = bytestream2_get_le32(&s->gb);
s->tile_attr.ySize = bytestream2_get_le32(&s->gb);
s->tile_attr.xSize = bytestream2_get_le32(gb);
s->tile_attr.ySize = bytestream2_get_le32(gb);
tileLevel = bytestream2_get_byte(&s->gb);
tileLevel = bytestream2_get_byte(gb);
s->tile_attr.level_mode = tileLevel & 0x0f;
s->tile_attr.level_round = (tileLevel >> 4) & 0x0f;
@ -1697,7 +1701,7 @@ static int decode_header(EXRContext *s, AVFrame *frame)
"string", 1)) >= 0) {
uint8_t key[256] = { 0 };
bytestream2_get_buffer(&s->gb, key, FFMIN(sizeof(key) - 1, var_size));
bytestream2_get_buffer(gb, key, FFMIN(sizeof(key) - 1, var_size));
av_dict_set(&metadata, "writer", key, 0);
continue;
@ -1708,21 +1712,21 @@ static int decode_header(EXRContext *s, AVFrame *frame)
goto fail;
}
s->avctx->framerate.num = bytestream2_get_le32(&s->gb);
s->avctx->framerate.den = bytestream2_get_le32(&s->gb);
s->avctx->framerate.num = bytestream2_get_le32(gb);
s->avctx->framerate.den = bytestream2_get_le32(gb);
continue;
} else if ((var_size = check_header_variable(s, "chunkCount",
"int", 23)) >= 0) {
s->chunk_count = bytestream2_get_le32(&s->gb);
s->chunk_count = bytestream2_get_le32(gb);
continue;
} else if ((var_size = check_header_variable(s, "type",
"string", 16)) >= 0) {
uint8_t key[256] = { 0 };
bytestream2_get_buffer(&s->gb, key, FFMIN(sizeof(key) - 1, var_size));
bytestream2_get_buffer(gb, key, FFMIN(sizeof(key) - 1, var_size));
if (strncmp("scanlineimage", key, var_size) &&
strncmp("tiledimage", key, var_size))
return AVERROR_PATCHWELCOME;
@ -1731,7 +1735,7 @@ static int decode_header(EXRContext *s, AVFrame *frame)
}
// Check if there are enough bytes for a header
if (bytestream2_get_bytes_left(&s->gb) <= 9) {
if (bytestream2_get_bytes_left(gb) <= 9) {
av_log(s->avctx, AV_LOG_ERROR, "Incomplete header\n");
ret = AVERROR_INVALIDDATA;
goto fail;
@ -1739,10 +1743,10 @@ static int decode_header(EXRContext *s, AVFrame *frame)
// Process unknown variables
for (i = 0; i < 2; i++) // value_name and value_type
while (bytestream2_get_byte(&s->gb) != 0);
while (bytestream2_get_byte(gb) != 0);
// Skip variable length
bytestream2_skip(&s->gb, bytestream2_get_le32(&s->gb));
bytestream2_skip(gb, bytestream2_get_le32(gb));
}
if (s->compression == EXR_UNKN) {
@ -1759,7 +1763,7 @@ static int decode_header(EXRContext *s, AVFrame *frame)
}
}
if (bytestream2_get_bytes_left(&s->gb) <= 0) {
if (bytestream2_get_bytes_left(gb) <= 0) {
av_log(s->avctx, AV_LOG_ERROR, "Incomplete frame.\n");
ret = AVERROR_INVALIDDATA;
goto fail;
@ -1768,7 +1772,7 @@ static int decode_header(EXRContext *s, AVFrame *frame)
frame->metadata = metadata;
// aaand we are done
bytestream2_skip(&s->gb, 1);
bytestream2_skip(gb, 1);
return 0;
fail:
av_dict_free(&metadata);
@ -1779,6 +1783,7 @@ static int decode_frame(AVCodecContext *avctx, void *data,
int *got_frame, AVPacket *avpkt)
{
EXRContext *s = avctx->priv_data;
GetByteContext *gb = &s->gb;
ThreadFrame frame = { .f = data };
AVFrame *picture = data;
uint8_t *ptr;
@ -1791,7 +1796,7 @@ static int decode_frame(AVCodecContext *avctx, void *data,
uint64_t start_next_scanline;
PutByteContext offset_table_writer;
bytestream2_init(&s->gb, avpkt->data, avpkt->size);
bytestream2_init(gb, avpkt->data, avpkt->size);
if ((ret = decode_header(s, picture)) < 0)
return ret;
@ -1893,14 +1898,14 @@ static int decode_frame(AVCodecContext *avctx, void *data,
if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
return ret;
if (bytestream2_get_bytes_left(&s->gb)/8 < nb_blocks)
if (bytestream2_get_bytes_left(gb)/8 < nb_blocks)
return AVERROR_INVALIDDATA;
// check offset table and recreate it if need
if (!s->is_tile && bytestream2_peek_le64(&s->gb) == 0) {
if (!s->is_tile && bytestream2_peek_le64(gb) == 0) {
av_log(s->avctx, AV_LOG_DEBUG, "recreating invalid scanline offset table\n");
start_offset_table = bytestream2_tell(&s->gb);
start_offset_table = bytestream2_tell(gb);
start_next_scanline = start_offset_table + nb_blocks * 8;
bytestream2_init_writer(&offset_table_writer, &avpkt->data[start_offset_table], nb_blocks * 8);
@ -1909,10 +1914,10 @@ static int decode_frame(AVCodecContext *avctx, void *data,
bytestream2_put_le64(&offset_table_writer, start_next_scanline);
/* get len of next scanline */
bytestream2_seek(&s->gb, start_next_scanline + 4, SEEK_SET);/* skip line number */
start_next_scanline += (bytestream2_get_le32(&s->gb) + 8);
bytestream2_seek(gb, start_next_scanline + 4, SEEK_SET);/* skip line number */
start_next_scanline += (bytestream2_get_le32(gb) + 8);
}
bytestream2_seek(&s->gb, start_offset_table, SEEK_SET);
bytestream2_seek(gb, start_offset_table, SEEK_SET);
}
// save pointer we are going to use in decode_block

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