avutil/frame: also align data pointers in av_frame_get_buffer()

This avoids unpleasant surprises to av_frame_get_buffer callers that explicitly specified 64-byte alignment and didn't get AVFrame.data pointers that are 64-byte aligned. For example, see https://github.com/sekrit-twc/zimg/issues/212 Although the zscale issue has already been resolved by other means it would still be prudent to improve the behavior of av_frame_get_buffer to fix any unknown and future instances of similar issues.

Pavel Koshevoy committed 1 year ago

Commit 46cb7b81 parent ea91d974 files · +25 −9Browse files

Unified · Split

4 files

doc/APIchanges +4 −0
libavutil/frame.c +16 −5
libavutil/frame.h +4 −3
libavutil/version.h +1 −1

doc/APIchanges+4−0

@@ -2,6 +2,10 @@ The last version increases of all libraries were on 2024-03-07 · 1 unmodified line
2	2
3	3	API changes, most recent first:
4	4
	5	+2024-11-16 - xxxxxxxxxx - lavu 59.47.101 - frame.h
	6	+ av_frame_get_buffer() now also aligns the data pointers according to
	7	+ the requested alignment.
	8	+
5	9	2024-11-13 - xxxxxxxxxx - lavu 59.47.100 - channel_layout.h
6	10	Add AV_CHAN_BINAURAL_LEFT, AV_CHAN_BINAURAL_RIGHT
7	11	Add AV_CH_BINAURAL_LEFT, AV_CH_BINAURAL_RIGHT

libavutil/frame.c+16−5

@@ -210,7 +210,7 @@ static int get_video_buffer(AVFrame *frame, int align) · 209 unmodified lines
210	210	padded_height, linesizes)) < 0)
211	211	return ret;
212	212
213		− total_size = 4*plane_padding;
	213	+ total_size = 4 * plane_padding + 4 * align;
214	214	for (int i = 0; i < 4; i++) {
215	215	if (sizes[i] > SIZE_MAX - total_size)
216	216	return AVERROR(EINVAL);
@@ -230,6 +230,7 @@ static int get_video_buffer(AVFrame *frame, int align) · 13 unmodified lines
230	230	for (int i = 1; i < 4; i++) {
231	231	if (frame->data[i])
232	232	frame->data[i] += i * plane_padding;
	233	+ frame->data[i] = (uint8_t *)FFALIGN((uintptr_t)frame->data[i], align);
233	234	}
234	235
235	236	frame->extended_data = frame->data;
@@ -244,6 +245,7 @@ static int get_audio_buffer(AVFrame *frame, int align) · 8 unmodified lines
244	245	{
245	246	int planar = av_sample_fmt_is_planar(frame->format);
246	247	int channels, planes;
	248	+ size_t size;
247	249	int ret;
248	250
249	251	channels = frame->ch_layout.nb_channels;
@@ -256,6 +258,9 @@ static int get_audio_buffer(AVFrame *frame, int align) · 6 unmodified lines
256	258	return ret;
257	259	}
258	260
	261	+ if (align <= 0)
	262	+ align = ALIGN;
	263	+
259	264	if (planes > AV_NUM_DATA_POINTERS) {
260	265	frame->extended_data = av_calloc(planes,
261	266	sizeof(*frame->extended_data));
@@ -270,21 +275,27 @@ static int get_audio_buffer(AVFrame *frame, int align) · 8 unmodified lines
270	275	} else
271	276	frame->extended_data = frame->data;
272	277
	278	+ if (frame->linesize[0] > SIZE_MAX - align)
	279	+ return AVERROR(EINVAL);
	280	+ size = frame->linesize[0] + (size_t)align;
	281	+
273	282	for (int i = 0; i < FFMIN(planes, AV_NUM_DATA_POINTERS); i++) {
274		− frame->buf[i] = av_buffer_alloc(frame->linesize[0]);
	283	+ frame->buf[i] = av_buffer_alloc(size);
275	284	if (!frame->buf[i]) {
276	285	av_frame_unref(frame);
277	286	return AVERROR(ENOMEM);
278	287	}
279		− frame->extended_data[i] = frame->data[i] = frame->buf[i]->data;
	288	+ frame->extended_data[i] = frame->data[i] =
	289	+ (uint8_t *)FFALIGN((uintptr_t)frame->buf[i]->data, align);
280	290	}
281	291	for (int i = 0; i < planes - AV_NUM_DATA_POINTERS; i++) {
282		− frame->extended_buf[i] = av_buffer_alloc(frame->linesize[0]);
	292	+ frame->extended_buf[i] = av_buffer_alloc(size);
283	293	if (!frame->extended_buf[i]) {
284	294	av_frame_unref(frame);
285	295	return AVERROR(ENOMEM);
286	296	}
287		− frame->extended_data[i + AV_NUM_DATA_POINTERS] = frame->extended_buf[i]->data;
	297	+ frame->extended_data[i + AV_NUM_DATA_POINTERS] =
	298	+ (uint8_t *)FFALIGN((uintptr_t)frame->extended_buf[i]->data, align);
288	299	}
289	300	return 0;
290	301

libavutil/frame.h+4−3

@@ -887,9 +887,10 @@ void av_frame_move_ref(AVFrame dst, AVFrame src); · 886 unmodified lines
887	887	* cases.
888	888	*
889	889	* @param frame frame in which to store the new buffers.
890		− * @param align Required buffer size alignment. If equal to 0, alignment will be
891		− * chosen automatically for the current CPU. It is highly
892		− * recommended to pass 0 here unless you know what you are doing.
	890	+ * @param align Required buffer size and data pointer alignment. If equal to 0,
	891	+ * alignment will be chosen automatically for the current CPU.
	892	+ * It is highly recommended to pass 0 here unless you know what
	893	+ * you are doing.
893	894	*
894	895	* @return 0 on success, a negative AVERROR on error.
895	896	*/

libavutil/version.h+1−1

@@ -80,7 +80,7 @@ · 79 unmodified lines
80	80
81	81	#define LIBAVUTIL_VERSION_MAJOR 59
82	82	#define LIBAVUTIL_VERSION_MINOR 47
83		−#define LIBAVUTIL_VERSION_MICRO 100
	83	+#define LIBAVUTIL_VERSION_MICRO 101
84	84
85	85	#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
86	86	LIBAVUTIL_VERSION_MINOR, \

avutil/frame: also align data pointers in av_frame_get_buffer()

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