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avcodec/mpeg12dec: switch to AVBufferRef buffer for a53 caption

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Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
This commit is contained in:
Limin Wang 2020-06-21 20:57:22 +08:00
parent a0b6df0a39
commit a705bcd763
1 changed files with 39 additions and 44 deletions
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83
libavcodec/mpeg12dec.c
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@ -57,8 +57,7 @@ typedef struct Mpeg1Context {
AVPanScan pan_scan; /* some temporary storage for the panscan */
AVStereo3D stereo3d;
int has_stereo3d;
uint8_t *a53_caption;
int a53_caption_size;
AVBufferRef *a53_buf_ref;
uint8_t afd;
int has_afd;
int slice_count;
@ -1635,13 +1634,13 @@ static int mpeg_field_start(MpegEncContext *s, const uint8_t *buf, int buf_size)
return AVERROR(ENOMEM);
memcpy(pan_scan->data, &s1->pan_scan, sizeof(s1->pan_scan));
if (s1->a53_caption) {
AVFrameSideData *sd = av_frame_new_side_data(
if (s1->a53_buf_ref) {
AVFrameSideData *sd = av_frame_new_side_data_from_buf(
s->current_picture_ptr->f, AV_FRAME_DATA_A53_CC,
s1->a53_caption_size);
if (sd)
memcpy(sd->data, s1->a53_caption, s1->a53_caption_size);
av_freep(&s1->a53_caption);
s1->a53_buf_ref);
if (!sd)
av_buffer_unref(&s1->a53_buf_ref);
s1->a53_buf_ref = NULL;
}
if (s1->has_stereo3d) {
@ -2242,26 +2241,18 @@ static int mpeg_decode_a53_cc(AVCodecContext *avctx,
/* extract A53 Part 4 CC data */
int cc_count = p[5] & 0x1f;
if (cc_count > 0 && buf_size >= 7 + cc_count * 3) {
if (s1->a53_caption && s1->a53_caption_size > 0) {
uint8_t *old_a53_caption = s1->a53_caption;
int old_a53_caption_size = s1->a53_caption_size;
int old_size = s1->a53_buf_ref ? s1->a53_buf_ref->size : 0;
const uint64_t new_size = (old_size + cc_count
* UINT64_C(3));
int ret;
if (new_size > INT_MAX)
return AVERROR(EINVAL);
ret = av_buffer_realloc(&s1->a53_buf_ref, new_size);
if (ret >= 0)
memcpy(s1->a53_buf_ref->data + old_size, p + 7, cc_count * UINT64_C(3));
s1->a53_caption_size = old_a53_caption_size + cc_count * 3;
s1->a53_caption = av_malloc(s1->a53_caption_size);
if (s1->a53_caption) {
memcpy(s1->a53_caption, old_a53_caption, old_a53_caption_size);
memcpy(s1->a53_caption + old_a53_caption_size, p + 7, cc_count * 3);
}
av_freep(&old_a53_caption);
} else {
s1->a53_caption_size = cc_count * 3;
s1->a53_caption = av_malloc(s1->a53_caption_size);
if (s1->a53_caption)
memcpy(s1->a53_caption, p + 7, s1->a53_caption_size);
}
if (!s1->a53_caption) {
s1->a53_caption_size = 0;
}
avctx->properties |= FF_CODEC_PROPERTY_CLOSED_CAPTIONS;
}
return 1;
@ -2270,19 +2261,21 @@ static int mpeg_decode_a53_cc(AVCodecContext *avctx,
/* extract SCTE-20 CC data */
GetBitContext gb;
int cc_count = 0;
int i;
int i, ret;
init_get_bits(&gb, p + 2, buf_size - 2);
cc_count = get_bits(&gb, 5);
if (cc_count > 0) {
av_freep(&s1->a53_caption);
s1->a53_caption_size = cc_count * 3;
s1->a53_caption = av_mallocz(s1->a53_caption_size);
if (!s1->a53_caption) {
s1->a53_caption_size = 0;
} else {
int old_size = s1->a53_buf_ref ? s1->a53_buf_ref->size : 0;
const uint64_t new_size = (old_size + cc_count
* UINT64_C(3));
if (new_size > INT_MAX)
return AVERROR(EINVAL);
ret = av_buffer_realloc(&s1->a53_buf_ref, new_size);
if (ret >= 0) {
uint8_t field, cc1, cc2;
uint8_t *cap = s1->a53_caption;
uint8_t *cap = s1->a53_buf_ref->data;
for (i = 0; i < cc_count && get_bits_left(&gb) >= 26; i++) {
skip_bits(&gb, 2); // priority
field = get_bits(&gb, 2);
@ -2334,21 +2327,23 @@ static int mpeg_decode_a53_cc(AVCodecContext *avctx,
* on the even field. There also exist DVDs in the wild that encode an odd field count and the
* caption_extra_field_added/caption_odd_field_first bits change per packet to allow that. */
int cc_count = 0;
int i;
int i, ret;
// There is a caption count field in the data, but it is often
// incorrect. So count the number of captions present.
for (i = 5; i + 6 <= buf_size && ((p[i] & 0xfe) == 0xfe); i += 6)
cc_count++;
// Transform the DVD format into A53 Part 4 format
if (cc_count > 0) {
av_freep(&s1->a53_caption);
s1->a53_caption_size = cc_count * 6;
s1->a53_caption = av_malloc(s1->a53_caption_size);
if (!s1->a53_caption) {
s1->a53_caption_size = 0;
} else {
int old_size = s1->a53_buf_ref ? s1->a53_buf_ref->size : 0;
const uint64_t new_size = (old_size + cc_count
* UINT64_C(6));
if (new_size > INT_MAX)
return AVERROR(EINVAL);
ret = av_buffer_realloc(&s1->a53_buf_ref, new_size);
if (ret >= 0) {
uint8_t field1 = !!(p[4] & 0x80);
uint8_t *cap = s1->a53_caption;
uint8_t *cap = s1->a53_buf_ref->data;
p += 5;
for (i = 0; i < cc_count; i++) {
cap[0] = (p[0] == 0xff && field1) ? 0xfc : 0xfd;
@ -2886,7 +2881,7 @@ static av_cold int mpeg_decode_end(AVCodecContext *avctx)
Mpeg1Context *s = avctx->priv_data;
ff_mpv_common_end(&s->mpeg_enc_ctx);
av_freep(&s->a53_caption);
av_buffer_unref(&s->a53_buf_ref);
return 0;
}