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HEVC parser: decode VUI block properly, handle timing info better
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@perexg
perexg committed Sep 25, 2015
1 parent 095156f commit d844b34
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Showing 2 changed files with 106 additions and 34 deletions.
2 changes: 1 addition & 1 deletion src/parsers/parser_h264.c
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Expand Up @@ -154,7 +154,7 @@ static const uint16_t h264_aspect[17][2] = {
static int
decode_vui(h264_sps_t *sps, bitstream_t *bs)
{
sps->aspect_num = 0;
sps->aspect_num = 1;
sps->aspect_den = 1;

if (read_bits1(bs)) {
Expand Down
138 changes: 105 additions & 33 deletions src/parsers/parser_hevc.c
View file
Expand Up @@ -1203,17 +1203,23 @@ typedef struct hevc_vps {
uint32_t time_scale;
} hevc_vps_t;

typedef struct hevc_vui {
struct {
uint32_t num;
uint32_t den;
} sar;
uint32_t num_units_in_tick;
uint32_t time_scale;
} hevc_vui_t;

typedef struct hevc_sps {
uint8_t valid: 1;
uint8_t vps_id;
uint32_t width;
uint32_t height;
uint32_t ctb_width;
uint32_t ctb_height;
struct {
uint32_t num;
uint32_t den;
} sar;
hevc_vui_t vui;
} hevc_sps_t;

typedef struct hevc_pps {
Expand Down Expand Up @@ -1327,22 +1333,91 @@ hevc_decode_vps(elementary_stream_t *st, bitstream_t *bs)
for (v = 0; v < max_layer_id; v++)
skip_bits1(bs); /* layer_id_included */

if (!read_bits1(bs)) /* vps_timing_info_present */
return;
vps->valid = 1;

vps->num_units_in_tick = read_bits(bs, 32);
vps->time_scale = read_bits(bs, 32);
if (!read_bits1(bs)) { /* vps_timing_info_present */
vps->num_units_in_tick = read_bits(bs, 32);
vps->time_scale = read_bits(bs, 32);
}
}

vps->valid = 1;
static int
hevc_decode_vui(hevc_vui_t *vui, bitstream_t *bs)
{
uint32_t u, sar_num, sar_den;
bitstream_t backup;

sar_num = 1;
sar_den = 1;
if (read_bits1(bs)) { /* sar_present */
u = read_bits(bs, 8);
if (u < ARRAY_SIZE(vui_sar)) {
sar_num = vui_sar[u][0];
sar_den = vui_sar[u][1];
} else if (u == 255) {
sar_num = read_bits(bs, 16);
sar_den = read_bits(bs, 16);
} else
return -1;
}
vui->sar.num = sar_num;
vui->sar.den = sar_den;

if (read_bits1(bs)) /* overscan_info_present */
skip_bits1(bs); /* overscan_appropriate */

if (read_bits1(bs)) { /* video_signal_type_present */
skip_bits(bs, 3); /* video_format */
skip_bits1(bs); /* video_full_range */
if (read_bits1(bs)) { /* colour_description_present */
skip_bits(bs, 8); /* colour_primaries */
skip_bits(bs, 8); /* transfer_characteristic */
skip_bits(bs, 8); /* matrix_coeffs */
}
}

if (read_bits1(bs)) { /* chroma_loc_info_present */
read_golomb_ue(bs); /* chroma_sample_loc_type_top_field */
read_golomb_ue(bs); /* chroma_sample_loc_type_bottom_field */
}

skip_bits1(bs); /* neutra_chroma_indication_flag */
skip_bits1(bs); /* field_seq_flag */
skip_bits1(bs); /* frame_field_info_present_flag */

if (remaining_bits(bs) >= 68 && show_bits(bs, 21) == 0x100000)
u = 0; /* Invalid default display window */
else
u = read_bits1(bs); /* default_display_window */
/* Backup context in case an alternate header is detected */
memcpy(&backup, bs, sizeof(backup));
if (u) { /* default_display_window */
read_golomb_ue(bs); /* left_offset */
read_golomb_ue(bs); /* right_offset */
read_golomb_ue(bs); /* top_offset */
read_golomb_ue(bs); /* bottom_offset */
}

if (read_bits1(bs)) { /* vui_timing_info_present */
if (remaining_bits(bs) < 66) {
/* Strange VUI timing information */
memcpy(bs, &backup, sizeof(backup));
}
vui->num_units_in_tick = read_bits(bs, 32);
vui->time_scale = read_bits(bs, 32);
}

return 0;
}

void
hevc_decode_sps(elementary_stream_t *st, bitstream_t *bs)
{
hevc_private_t *p;
hevc_vps_t *vps;
hevc_sps_t *sps;
uint32_t vps_id, sps_id, max_sub_layers, u, v, i;
uint32_t width, height, sar_num, sar_den;
uint32_t width, height;
uint32_t chroma_format_idc, bit_depth, bit_depth_chroma;
uint32_t log2_max_poc_lsb;
uint32_t log2_min_cb_size, log2_min_tb_size;
Expand All @@ -1359,7 +1434,10 @@ hevc_decode_sps(elementary_stream_t *st, bitstream_t *bs)
skip_bits(bs, 15); /* NAL type, Layer ID, Temporal ID */

vps_id = read_bits(bs, 4);
if (vps_id >= MAX_VPS_COUNT || !p->vps[vps_id].valid)
if (vps_id >= MAX_VPS_COUNT)
return;
vps = &p->vps[vps_id];
if (!vps->valid)
return;

max_sub_layers = read_bits(bs, 3) + 1;
Expand Down Expand Up @@ -1488,28 +1566,17 @@ hevc_decode_sps(elementary_stream_t *st, bitstream_t *bs)
skip_bits1(bs); /* sps_temporal_mvp_enabled_flag */
skip_bits1(bs); /* sps_strong_intra_smoothing_enable_flag */

sar_num = 0;
sar_den = 1;
if (read_bits1(bs)) { /* vui_present */
if (read_bits1(bs)) { /* sar_present */
u = read_bits(bs, 8);
if (u < ARRAY_SIZE(vui_sar)) {
sar_num = vui_sar[u][0];
sar_den = vui_sar[u][1];
} else if (u == 255) {
sar_num = read_bits(bs, 16);
sar_den = read_bits(bs, 16);
} else
return;
}
}
if (read_bits1(bs)) /* vui_present */
if (hevc_decode_vui(&sps->vui, bs))
return;

if (!vps->num_units_in_tick && !vps->time_scale &&
!sps->vui.num_units_in_tick && !sps->vui.time_scale)
return;

sps->width = width;
sps->height = height;

sps->sar.num = sar_num;
sps->sar.den = sar_den;

log2_ctb_size = log2_min_cb_size +
log2_diff_max_min_coding_block_size;

Expand Down Expand Up @@ -1623,14 +1690,19 @@ hevc_decode_slice_header(struct elementary_stream *st, bitstream_t *bs,

vps = &p->vps[vps_id];

d = 180000 * (uint64_t)vps->num_units_in_tick / (uint64_t)vps->time_scale;
d = 0;
if (sps->vui.time_scale) {
d = 180000 * (uint64_t)sps->vui.num_units_in_tick / (uint64_t)sps->vui.time_scale;
} else if (vps->time_scale) {
d = 180000 * (uint64_t)vps->num_units_in_tick / (uint64_t)vps->time_scale;
}

if (width && height && d)
parser_set_stream_vparam(st, width, height, d);

if (sps->sar.num && sps->sar.den) {
width *= sps->sar.num;
height *= sps->sar.den;
if (sps->vui.sar.num && sps->vui.sar.den) {
width *= sps->vui.sar.num;
height *= sps->vui.sar.den;
if (width && height) {
v = gcdU32(width, height);
st->es_aspect_num = width / v;
Expand Down

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