Re: [FFmpeg-devel] [PATCH v2] h264: Support multi-field closed captions by using AVBufferRef and not resetting per field
On 8/17/2018 7:41 AM, jos...@ob-encoder.com wrote:
> From: Kieran Kunhya
>
> Signed-off-by: Josh de Kock
> ---
> libavcodec/h264_sei.c | 15 ---
> libavcodec/h264_sei.h | 3 +--
> libavcodec/h264_slice.c | 26 ++
> libavcodec/h264dec.c| 5 +++--
> 4 files changed, 30 insertions(+), 19 deletions(-)
>
> diff --git a/libavcodec/h264_sei.c b/libavcodec/h264_sei.c
> index 6499086210..43593d34d2 100644
> --- a/libavcodec/h264_sei.c
> +++ b/libavcodec/h264_sei.c
> @@ -51,8 +51,7 @@ void ff_h264_sei_uninit(H264SEIContext *h)
> h->display_orientation.present = 0;
> h->afd.present = 0;
>
> -h->a53_caption.a53_caption_size = 0;
> -av_freep(>a53_caption.a53_caption);
> +av_buffer_unref(>a53_caption.buf_ref);
> }
>
> static int decode_picture_timing(H264SEIPictureTiming *h, GetBitContext *gb,
> @@ -169,7 +168,8 @@ static int
> decode_registered_user_data_closed_caption(H264SEIA53Caption *h,
> size -= 2;
>
> if (cc_count && size >= cc_count * 3) {
> -const uint64_t new_size = (h->a53_caption_size + cc_count
> +int old_size = h->buf_ref ? h->buf_ref->size : 0;
> +const uint64_t new_size = (old_size + cc_count
> * UINT64_C(3));
> int i, ret;
>
> @@ -177,14 +177,15 @@ static int
> decode_registered_user_data_closed_caption(H264SEIA53Caption *h,
> return AVERROR(EINVAL);
>
> /* Allow merging of the cc data from two fields. */
> -ret = av_reallocp(>a53_caption, new_size);
> +ret = av_buffer_realloc(>buf_ref, new_size);
> if (ret < 0)
> return ret;
>
> +/* Use of av_buffer_realloc assumes buffer is writeable */
> for (i = 0; i < cc_count; i++) {
> -h->a53_caption[h->a53_caption_size++] = get_bits(gb, 8);
> -h->a53_caption[h->a53_caption_size++] = get_bits(gb, 8);
> -h->a53_caption[h->a53_caption_size++] = get_bits(gb, 8);
> +h->buf_ref->data[old_size++] = get_bits(gb, 8);
> +h->buf_ref->data[old_size++] = get_bits(gb, 8);
> +h->buf_ref->data[old_size++] = get_bits(gb, 8);
> }
>
> skip_bits(gb, 8); // marker_bits
> diff --git a/libavcodec/h264_sei.h b/libavcodec/h264_sei.h
> index a169a10e49..5b7c8ef9d8 100644
> --- a/libavcodec/h264_sei.h
> +++ b/libavcodec/h264_sei.h
> @@ -95,8 +95,7 @@ typedef struct H264SEIAFD {
> } H264SEIAFD;
>
> typedef struct H264SEIA53Caption {
> -int a53_caption_size;
> -uint8_t *a53_caption;
> +AVBufferRef *buf_ref;
> } H264SEIA53Caption;
>
> typedef struct H264SEIUnregistered {
> diff --git a/libavcodec/h264_slice.c b/libavcodec/h264_slice.c
> index ede9a1a6ea..f31c9a2579 100644
> --- a/libavcodec/h264_slice.c
> +++ b/libavcodec/h264_slice.c
> @@ -430,6 +430,15 @@ int ff_h264_update_thread_context(AVCodecContext *dst,
>
> h->frame_recovered = h1->frame_recovered;
>
> +av_buffer_unref(>sei.a53_caption.buf_ref);
> +h->sei.a53_caption.buf_ref = NULL;
Unneeded, av_buffer_unref() already would have set the pointer to NULL.
> +
> +if (h1->sei.a53_caption.buf_ref) {
> +h->sei.a53_caption.buf_ref =
> av_buffer_ref(h1->sei.a53_caption.buf_ref);
> +if (!h->sei.a53_caption.buf_ref)
> +return AVERROR(ENOMEM);
> +}
> +
> if (!h->cur_pic_ptr)
> return 0;
>
> @@ -1269,15 +1278,16 @@ static int h264_export_frame_props(H264Context *h)
> }
> }
>
> -if (h->sei.a53_caption.a53_caption) {
> +if (h->sei.a53_caption.buf_ref) {
> H264SEIA53Caption *a53 = >sei.a53_caption;
> -AVFrameSideData *sd = av_frame_new_side_data(cur->f,
> - AV_FRAME_DATA_A53_CC,
> - a53->a53_caption_size);
> -if (sd)
> -memcpy(sd->data, a53->a53_caption, a53->a53_caption_size);
> -av_freep(>a53_caption);
> -a53->a53_caption_size = 0;
> +
> +AVFrameSideData *sd = av_frame_new_side_data_from_buf(cur->f,
> AV_FRAME_DATA_A53_CC, av_buffer_ref(a53->buf_ref));
> +if (sd) {
> +av_buffer_unref(>buf_ref);
The doxy for av_frame_new_side_data_from_buf() states that on success it
takes ownership of the passed reference, but on failure said reference
remains owned by the caller. So what you're doing here is creating and
passing a reference that, if av_frame_new_side_data_from_buf() fails,
will leak.
What you need to do is directly pass a53->buf_ref to it, and then only
unref it if !sd.
I agree the semantics of av_frame_new_side_data_from_buf() are kinda
ugly and unlike other AVBufferRef functions, but it's too late to change
[FFmpeg-devel] [PATCH v2] h264: Support multi-field closed captions by using AVBufferRef and not resetting per field
From: Kieran Kunhya
Signed-off-by: Josh de Kock
---
libavcodec/h264_sei.c | 15 ---
libavcodec/h264_sei.h | 3 +--
libavcodec/h264_slice.c | 26 ++
libavcodec/h264dec.c| 5 +++--
4 files changed, 30 insertions(+), 19 deletions(-)
diff --git a/libavcodec/h264_sei.c b/libavcodec/h264_sei.c
index 6499086210..43593d34d2 100644
--- a/libavcodec/h264_sei.c
+++ b/libavcodec/h264_sei.c
@@ -51,8 +51,7 @@ void ff_h264_sei_uninit(H264SEIContext *h)
h->display_orientation.present = 0;
h->afd.present = 0;
-h->a53_caption.a53_caption_size = 0;
-av_freep(>a53_caption.a53_caption);
+av_buffer_unref(>a53_caption.buf_ref);
}
static int decode_picture_timing(H264SEIPictureTiming *h, GetBitContext *gb,
@@ -169,7 +168,8 @@ static int
decode_registered_user_data_closed_caption(H264SEIA53Caption *h,
size -= 2;
if (cc_count && size >= cc_count * 3) {
-const uint64_t new_size = (h->a53_caption_size + cc_count
+int old_size = h->buf_ref ? h->buf_ref->size : 0;
+const uint64_t new_size = (old_size + cc_count
* UINT64_C(3));
int i, ret;
@@ -177,14 +177,15 @@ static int
decode_registered_user_data_closed_caption(H264SEIA53Caption *h,
return AVERROR(EINVAL);
/* Allow merging of the cc data from two fields. */
-ret = av_reallocp(>a53_caption, new_size);
+ret = av_buffer_realloc(>buf_ref, new_size);
if (ret < 0)
return ret;
+/* Use of av_buffer_realloc assumes buffer is writeable */
for (i = 0; i < cc_count; i++) {
-h->a53_caption[h->a53_caption_size++] = get_bits(gb, 8);
-h->a53_caption[h->a53_caption_size++] = get_bits(gb, 8);
-h->a53_caption[h->a53_caption_size++] = get_bits(gb, 8);
+h->buf_ref->data[old_size++] = get_bits(gb, 8);
+h->buf_ref->data[old_size++] = get_bits(gb, 8);
+h->buf_ref->data[old_size++] = get_bits(gb, 8);
}
skip_bits(gb, 8); // marker_bits
diff --git a/libavcodec/h264_sei.h b/libavcodec/h264_sei.h
index a169a10e49..5b7c8ef9d8 100644
--- a/libavcodec/h264_sei.h
+++ b/libavcodec/h264_sei.h
@@ -95,8 +95,7 @@ typedef struct H264SEIAFD {
} H264SEIAFD;
typedef struct H264SEIA53Caption {
-int a53_caption_size;
-uint8_t *a53_caption;
+AVBufferRef *buf_ref;
} H264SEIA53Caption;
typedef struct H264SEIUnregistered {
diff --git a/libavcodec/h264_slice.c b/libavcodec/h264_slice.c
index ede9a1a6ea..f31c9a2579 100644
--- a/libavcodec/h264_slice.c
+++ b/libavcodec/h264_slice.c
@@ -430,6 +430,15 @@ int ff_h264_update_thread_context(AVCodecContext *dst,
h->frame_recovered = h1->frame_recovered;
+av_buffer_unref(>sei.a53_caption.buf_ref);
+h->sei.a53_caption.buf_ref = NULL;
+
+if (h1->sei.a53_caption.buf_ref) {
+h->sei.a53_caption.buf_ref =
av_buffer_ref(h1->sei.a53_caption.buf_ref);
+if (!h->sei.a53_caption.buf_ref)
+return AVERROR(ENOMEM);
+}
+
if (!h->cur_pic_ptr)
return 0;
@@ -1269,15 +1278,16 @@ static int h264_export_frame_props(H264Context *h)
}
}
-if (h->sei.a53_caption.a53_caption) {
+if (h->sei.a53_caption.buf_ref) {
H264SEIA53Caption *a53 = >sei.a53_caption;
-AVFrameSideData *sd = av_frame_new_side_data(cur->f,
- AV_FRAME_DATA_A53_CC,
- a53->a53_caption_size);
-if (sd)
-memcpy(sd->data, a53->a53_caption, a53->a53_caption_size);
-av_freep(>a53_caption);
-a53->a53_caption_size = 0;
+
+AVFrameSideData *sd = av_frame_new_side_data_from_buf(cur->f,
AV_FRAME_DATA_A53_CC, av_buffer_ref(a53->buf_ref));
+if (sd) {
+av_buffer_unref(>buf_ref);
+} else {
+return AVERROR(ENOMEM);
+}
+
h->avctx->properties |= FF_CODEC_PROPERTY_CLOSED_CAPTIONS;
}
diff --git a/libavcodec/h264dec.c b/libavcodec/h264dec.c
index 7494c7a8f2..8d115fa040 100644
--- a/libavcodec/h264dec.c
+++ b/libavcodec/h264dec.c
@@ -609,9 +609,10 @@ static int decode_nal_units(H264Context *h, const uint8_t
*buf, int buf_size)
if (!(avctx->flags2 & AV_CODEC_FLAG2_CHUNKS)) {
h->current_slice = 0;
-if (!h->first_field)
+if (!h->first_field) {
h->cur_pic_ptr = NULL;
-ff_h264_sei_uninit(>sei);
+ff_h264_sei_uninit(>sei);
+}
}
if (h->nal_length_size == 4) {
--
2.17.1
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