[FFmpeg-devel] [PATCH v4 02/23] avutil/frame: Prepare AVFrame for subtitle handling
softworkz
ffmpegagent at gmail.com
Sat May 28 16:25:02 EEST 2022
From: softworkz <softworkz at hotmail.com>
Root commit for adding subtitle filtering capabilities.
In detail:
- Add type (AVMediaType) field to AVFrame
Replaces previous way of distinction which was based on checking
width and height to determine whether a frame is audio or video
- Add subtitle fields to AVFrame
- Add new struct AVSubtitleArea, similar to AVSubtitleRect, but
different allocation logic. Cannot and must not be used
interchangeably, hence the new struct
Signed-off-by: softworkz <softworkz at hotmail.com>
---
libavutil/Makefile | 1 +
libavutil/frame.c | 211 +++++++++++++++++++++++++++++++++++++++------
libavutil/frame.h | 85 +++++++++++++++++-
libavutil/subfmt.c | 45 ++++++++++
libavutil/subfmt.h | 47 ++++++++++
5 files changed, 362 insertions(+), 27 deletions(-)
create mode 100644 libavutil/subfmt.c
diff --git a/libavutil/Makefile b/libavutil/Makefile
index 5fcdd68ca8..78f65c144a 100644
--- a/libavutil/Makefile
+++ b/libavutil/Makefile
@@ -162,6 +162,7 @@ OBJS = adler32.o \
slicethread.o \
spherical.o \
stereo3d.o \
+ subfmt.o \
threadmessage.o \
time.o \
timecode.o \
diff --git a/libavutil/frame.c b/libavutil/frame.c
index fbb869fffa..b24fdc5868 100644
--- a/libavutil/frame.c
+++ b/libavutil/frame.c
@@ -26,6 +26,7 @@
#include "imgutils.h"
#include "mem.h"
#include "samplefmt.h"
+#include "subfmt.h"
#include "hwcontext.h"
#if FF_API_OLD_CHANNEL_LAYOUT
@@ -52,6 +53,9 @@ const char *av_get_colorspace_name(enum AVColorSpace val)
return name[val];
}
#endif
+
+static int frame_copy_subtitles(AVFrame *dst, const AVFrame *src, int copy_data);
+
static void get_frame_defaults(AVFrame *frame)
{
memset(frame, 0, sizeof(*frame));
@@ -72,7 +76,12 @@ static void get_frame_defaults(AVFrame *frame)
frame->colorspace = AVCOL_SPC_UNSPECIFIED;
frame->color_range = AVCOL_RANGE_UNSPECIFIED;
frame->chroma_location = AVCHROMA_LOC_UNSPECIFIED;
- frame->flags = 0;
+ frame->num_subtitle_areas = 0;
+ frame->subtitle_areas = NULL;
+ frame->subtitle_header = NULL;
+ frame->repeat_sub = 0;
+ frame->subtitle_timing.start_pts = 0;
+ frame->subtitle_timing.duration = 0;
}
static void free_side_data(AVFrameSideData **ptr_sd)
@@ -251,6 +260,23 @@ FF_ENABLE_DEPRECATION_WARNINGS
}
+static int get_subtitle_buffer(AVFrame *frame)
+{
+ // Buffers in AVFrame->buf[] are not used in case of subtitle frames.
+ // To accomodate with existing code, checking ->buf[0] to determine
+ // whether a frame is ref-counted or has data, we're adding a 1-byte
+ // buffer here, which marks the subtitle frame to contain data.
+ frame->buf[0] = av_buffer_alloc(1);
+ if (!frame->buf[0]) {
+ av_frame_unref(frame);
+ return AVERROR(ENOMEM);
+ }
+
+ frame->extended_data = frame->data;
+
+ return 0;
+}
+
int av_frame_get_buffer(AVFrame *frame, int align)
{
if (frame->format < 0)
@@ -258,23 +284,41 @@ int av_frame_get_buffer(AVFrame *frame, int align)
FF_DISABLE_DEPRECATION_WARNINGS
if (frame->width > 0 && frame->height > 0)
- return get_video_buffer(frame, align);
+ frame->type = AVMEDIA_TYPE_VIDEO;
else if (frame->nb_samples > 0 &&
(av_channel_layout_check(&frame->ch_layout)
#if FF_API_OLD_CHANNEL_LAYOUT
|| frame->channel_layout || frame->channels > 0
#endif
))
- return get_audio_buffer(frame, align);
+ frame->type = AVMEDIA_TYPE_AUDIO;
FF_ENABLE_DEPRECATION_WARNINGS
- return AVERROR(EINVAL);
+ return av_frame_get_buffer2(frame, align);
+}
+
+int av_frame_get_buffer2(AVFrame *frame, int align)
+{
+ if (frame->format < 0)
+ return AVERROR(EINVAL);
+
+ switch (frame->type) {
+ case AVMEDIA_TYPE_VIDEO:
+ return get_video_buffer(frame, align);
+ case AVMEDIA_TYPE_AUDIO:
+ return get_audio_buffer(frame, align);
+ case AVMEDIA_TYPE_SUBTITLE:
+ return get_subtitle_buffer(frame);
+ default:
+ return AVERROR(EINVAL);
+ }
}
static int frame_copy_props(AVFrame *dst, const AVFrame *src, int force_copy)
{
int ret, i;
+ dst->type = src->type;
dst->key_frame = src->key_frame;
dst->pict_type = src->pict_type;
dst->sample_aspect_ratio = src->sample_aspect_ratio;
@@ -306,6 +350,12 @@ static int frame_copy_props(AVFrame *dst, const AVFrame *src, int force_copy)
dst->colorspace = src->colorspace;
dst->color_range = src->color_range;
dst->chroma_location = src->chroma_location;
+ dst->repeat_sub = src->repeat_sub;
+ dst->subtitle_timing.start_pts = src->subtitle_timing.start_pts;
+ dst->subtitle_timing.duration = src->subtitle_timing.duration;
+
+ if ((ret = av_buffer_replace(&dst->subtitle_header, src->subtitle_header)) < 0)
+ return ret;
av_dict_copy(&dst->metadata, src->metadata, 0);
@@ -353,6 +403,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
av_assert1(dst->ch_layout.nb_channels == 0 &&
dst->ch_layout.order == AV_CHANNEL_ORDER_UNSPEC);
+ dst->type = src->type;
dst->format = src->format;
dst->width = src->width;
dst->height = src->height;
@@ -385,7 +436,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
/* duplicate the frame data if it's not refcounted */
if (!src->buf[0]) {
- ret = av_frame_get_buffer(dst, 0);
+ ret = av_frame_get_buffer2(dst, 0);
if (ret < 0)
goto fail;
@@ -407,6 +458,10 @@ FF_ENABLE_DEPRECATION_WARNINGS
}
}
+ /* copy subtitle areas */
+ if (src->type == AVMEDIA_TYPE_SUBTITLE)
+ frame_copy_subtitles(dst, src, 0);
+
if (src->extended_buf) {
dst->extended_buf = av_calloc(src->nb_extended_buf,
sizeof(*dst->extended_buf));
@@ -476,7 +531,7 @@ AVFrame *av_frame_clone(const AVFrame *src)
void av_frame_unref(AVFrame *frame)
{
- int i;
+ unsigned i, n;
if (!frame)
return;
@@ -495,6 +550,21 @@ void av_frame_unref(AVFrame *frame)
av_buffer_unref(&frame->opaque_ref);
av_buffer_unref(&frame->private_ref);
+ av_buffer_unref(&frame->subtitle_header);
+
+ for (i = 0; i < frame->num_subtitle_areas; i++) {
+ AVSubtitleArea *area = frame->subtitle_areas[i];
+
+ for (n = 0; n < FF_ARRAY_ELEMS(area->buf); n++)
+ av_buffer_unref(&area->buf[n]);
+
+ av_freep(&area->text);
+ av_freep(&area->ass);
+ av_free(area);
+ }
+
+ av_freep(&frame->subtitle_areas);
+
if (frame->extended_data != frame->data)
av_freep(&frame->extended_data);
@@ -522,18 +592,28 @@ FF_ENABLE_DEPRECATION_WARNINGS
int av_frame_is_writable(AVFrame *frame)
{
- int i, ret = 1;
+ AVSubtitleArea *area;
+ int ret = 1;
/* assume non-refcounted frames are not writable */
if (!frame->buf[0])
return 0;
- for (i = 0; i < FF_ARRAY_ELEMS(frame->buf); i++)
+ for (unsigned i = 0; i < FF_ARRAY_ELEMS(frame->buf); i++)
if (frame->buf[i])
ret &= !!av_buffer_is_writable(frame->buf[i]);
- for (i = 0; i < frame->nb_extended_buf; i++)
+ for (unsigned i = 0; i < frame->nb_extended_buf; i++)
ret &= !!av_buffer_is_writable(frame->extended_buf[i]);
+ for (unsigned i = 0; i < frame->num_subtitle_areas; i++) {
+ area = frame->subtitle_areas[i];
+ if (area) {
+ for (unsigned n = 0; n < FF_ARRAY_ELEMS(area->buf); n++)
+ if (area->buf[n])
+ ret &= !!av_buffer_is_writable(area->buf[n]);
+ }
+ }
+
return ret;
}
@@ -549,6 +629,7 @@ int av_frame_make_writable(AVFrame *frame)
return 0;
memset(&tmp, 0, sizeof(tmp));
+ tmp.type = frame->type;
tmp.format = frame->format;
tmp.width = frame->width;
tmp.height = frame->height;
@@ -568,7 +649,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
if (frame->hw_frames_ctx)
ret = av_hwframe_get_buffer(frame->hw_frames_ctx, &tmp, 0);
else
- ret = av_frame_get_buffer(&tmp, 0);
+ ret = av_frame_get_buffer2(&tmp, 0);
if (ret < 0)
return ret;
@@ -603,7 +684,12 @@ AVBufferRef *av_frame_get_plane_buffer(AVFrame *frame, int plane)
uint8_t *data;
int planes, i;
- if (frame->nb_samples) {
+ switch(frame->type) {
+ case AVMEDIA_TYPE_VIDEO:
+ planes = 4;
+ break;
+ case AVMEDIA_TYPE_AUDIO:
+ {
int channels = frame->ch_layout.nb_channels;
#if FF_API_OLD_CHANNEL_LAYOUT
@@ -617,8 +703,11 @@ FF_ENABLE_DEPRECATION_WARNINGS
if (!channels)
return NULL;
planes = av_sample_fmt_is_planar(frame->format) ? channels : 1;
- } else
- planes = 4;
+ break;
+ }
+ default:
+ return NULL;
+ }
if (plane < 0 || plane >= planes || !frame->extended_data[plane])
return NULL;
@@ -752,24 +841,98 @@ FF_ENABLE_DEPRECATION_WARNINGS
return 0;
}
+static int av_subtitle_area2area(AVSubtitleArea *dst, const AVSubtitleArea *src, int copy_data)
+{
+ dst->x = src->x;
+ dst->y = src->y;
+ dst->w = src->w;
+ dst->h = src->h;
+ dst->nb_colors = src->nb_colors;
+ dst->type = src->type;
+ dst->flags = src->flags;
+
+ switch (dst->type) {
+ case AV_SUBTITLE_FMT_BITMAP:
+
+ for (unsigned i = 0; i < AV_NUM_BUFFER_POINTERS; i++) {
+ if (src->h > 0 && src->w > 0 && src->buf[i]) {
+ dst->buf[0] = av_buffer_ref(src->buf[i]);
+ if (!dst->buf[i])
+ return AVERROR(ENOMEM);
+
+ if (copy_data) {
+ const int ret = av_buffer_make_writable(&dst->buf[i]);
+ if (ret < 0)
+ return ret;
+ }
+
+ dst->linesize[i] = src->linesize[i];
+ }
+ }
+
+ memcpy(&dst->pal[0], &src->pal[0], sizeof(src->pal[0]) * 256);
+
+ break;
+ case AV_SUBTITLE_FMT_TEXT:
+
+ if (src->text) {
+ dst->text = av_strdup(src->text);
+ if (!dst->text)
+ return AVERROR(ENOMEM);
+ }
+
+ break;
+ case AV_SUBTITLE_FMT_ASS:
+
+ if (src->ass) {
+ dst->ass = av_strdup(src->ass);
+ if (!dst->ass)
+ return AVERROR(ENOMEM);
+ }
+
+ break;
+ default:
+
+ av_log(NULL, AV_LOG_ERROR, "Subtitle area has invalid format: %d", dst->type);
+ return AVERROR(ENOMEM);
+ }
+
+ return 0;
+}
+
+static int frame_copy_subtitles(AVFrame *dst, const AVFrame *src, int copy_data)
+{
+ dst->format = src->format;
+
+ dst->num_subtitle_areas = src->num_subtitle_areas;
+
+ if (src->num_subtitle_areas) {
+ dst->subtitle_areas = av_malloc_array(src->num_subtitle_areas, sizeof(AVSubtitleArea *));
+
+ for (unsigned i = 0; i < src->num_subtitle_areas; i++) {
+ dst->subtitle_areas[i] = av_mallocz(sizeof(AVSubtitleArea));
+ av_subtitle_area2area(dst->subtitle_areas[i], src->subtitle_areas[i], copy_data);
+ }
+ }
+
+ return 0;
+}
+
int av_frame_copy(AVFrame *dst, const AVFrame *src)
{
if (dst->format != src->format || dst->format < 0)
return AVERROR(EINVAL);
-FF_DISABLE_DEPRECATION_WARNINGS
- if (dst->width > 0 && dst->height > 0)
+ switch(dst->type) {
+ case AVMEDIA_TYPE_VIDEO:
return frame_copy_video(dst, src);
- else if (dst->nb_samples > 0 &&
- (av_channel_layout_check(&dst->ch_layout)
-#if FF_API_OLD_CHANNEL_LAYOUT
- || dst->channel_layout || dst->channels
-#endif
- ))
+ case AVMEDIA_TYPE_AUDIO:
return frame_copy_audio(dst, src);
-FF_ENABLE_DEPRECATION_WARNINGS
-
- return AVERROR(EINVAL);
+ case AVMEDIA_TYPE_SUBTITLE:
+ return frame_copy_subtitles(dst, src, 1);
+ default:
+ return AVERROR(EINVAL);
+ }
}
void av_frame_remove_side_data(AVFrame *frame, enum AVFrameSideDataType type)
diff --git a/libavutil/frame.h b/libavutil/frame.h
index 33fac2054c..dd36f5b27c 100644
--- a/libavutil/frame.h
+++ b/libavutil/frame.h
@@ -25,7 +25,6 @@
#ifndef AVUTIL_FRAME_H
#define AVUTIL_FRAME_H
-#include <stddef.h>
#include <stdint.h>
#include "avutil.h"
@@ -35,6 +34,7 @@
#include "rational.h"
#include "samplefmt.h"
#include "pixfmt.h"
+#include "subfmt.h"
#include "version.h"
@@ -293,7 +293,7 @@ typedef struct AVRegionOfInterest {
} AVRegionOfInterest;
/**
- * This structure describes decoded (raw) audio or video data.
+ * This structure describes decoded (raw) audio, video or subtitle data.
*
* AVFrame must be allocated using av_frame_alloc(). Note that this only
* allocates the AVFrame itself, the buffers for the data must be managed
@@ -407,7 +407,7 @@ typedef struct AVFrame {
/**
* format of the frame, -1 if unknown or unset
* Values correspond to enum AVPixelFormat for video frames,
- * enum AVSampleFormat for audio)
+ * enum AVSampleFormat for audio, AVSubtitleType for subtitles)
*/
int format;
@@ -702,6 +702,53 @@ typedef struct AVFrame {
* Channel layout of the audio data.
*/
AVChannelLayout ch_layout;
+
+ /**
+ * Media type of the frame (audio, video, subtitles..)
+ *
+ * See AVMEDIA_TYPE_xxx
+ */
+ enum AVMediaType type;
+
+ /**
+ * Number of items in the @ref subtitle_areas array.
+ */
+ unsigned num_subtitle_areas;
+
+ /**
+ * Array of subtitle areas, may be empty.
+ */
+ AVSubtitleArea **subtitle_areas;
+
+ /**
+ * Header containing style information for text subtitles.
+ */
+ AVBufferRef *subtitle_header;
+
+ /**
+ * Indicates that a subtitle frame is a repeated frame for arbitrating flow
+ * in a filter graph.
+ * The field subtitle_timing.start_pts always indicates the original presentation
+ * time, while the frame's pts field may be different.
+ */
+ int repeat_sub;
+
+ struct SubtitleTiming
+ {
+ /**
+ * The display start time, in AV_TIME_BASE.
+ *
+ * For subtitle frames, AVFrame.pts is populated from the packet pts value,
+ * which is not always the same as this value.
+ */
+ int64_t start_pts;
+
+ /**
+ * Display duration, in AV_TIME_BASE.
+ */
+ int64_t duration;
+
+ } subtitle_timing;
} AVFrame;
@@ -778,6 +825,8 @@ void av_frame_move_ref(AVFrame *dst, AVFrame *src);
/**
* Allocate new buffer(s) for audio or video data.
*
+ * Note: For subtitle data, use av_frame_get_buffer2
+ *
* The following fields must be set on frame before calling this function:
* - format (pixel format for video, sample format for audio)
* - width and height for video
@@ -797,9 +846,39 @@ void av_frame_move_ref(AVFrame *dst, AVFrame *src);
* recommended to pass 0 here unless you know what you are doing.
*
* @return 0 on success, a negative AVERROR on error.
+ *
+ * @deprecated Use @ref av_frame_get_buffer2 instead and set @ref AVFrame.type
+ * before calling.
*/
+attribute_deprecated
int av_frame_get_buffer(AVFrame *frame, int align);
+/**
+ * Allocate new buffer(s) for audio, video or subtitle data.
+ *
+ * The following fields must be set on frame before calling this function:
+ * - format (pixel format for video, sample format for audio)
+ * - width and height for video
+ * - nb_samples and channel_layout for audio
+ * - type (AVMediaType)
+ *
+ * This function will fill AVFrame.data and AVFrame.buf arrays and, if
+ * necessary, allocate and fill AVFrame.extended_data and AVFrame.extended_buf.
+ * For planar formats, one buffer will be allocated for each plane.
+ *
+ * @warning: if frame already has been allocated, calling this function will
+ * leak memory. In addition, undefined behavior can occur in certain
+ * cases.
+ *
+ * @param frame frame in which to store the new buffers.
+ * @param align Required buffer size alignment. If equal to 0, alignment will be
+ * chosen automatically for the current CPU. It is highly
+ * recommended to pass 0 here unless you know what you are doing.
+ *
+ * @return 0 on success, a negative AVERROR on error.
+ */
+int av_frame_get_buffer2(AVFrame *frame, int align);
+
/**
* Check if the frame data is writable.
*
diff --git a/libavutil/subfmt.c b/libavutil/subfmt.c
new file mode 100644
index 0000000000..c72ebe2a43
--- /dev/null
+++ b/libavutil/subfmt.c
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2021 softworkz
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <string.h>
+#include "common.h"
+#include "subfmt.h"
+
+static const char sub_fmt_info[AV_SUBTITLE_FMT_NB][24] = {
+ [AV_SUBTITLE_FMT_UNKNOWN] = "Unknown subtitle format",
+ [AV_SUBTITLE_FMT_BITMAP] = "Graphical subtitles",
+ [AV_SUBTITLE_FMT_TEXT] = "Text subtitles (plain)",
+ [AV_SUBTITLE_FMT_ASS] = "Text subtitles (ass)",
+};
+
+const char *av_get_subtitle_fmt_name(enum AVSubtitleType sub_fmt)
+{
+ if (sub_fmt < 0 || sub_fmt >= AV_SUBTITLE_FMT_NB)
+ return NULL;
+ return sub_fmt_info[sub_fmt];
+}
+
+enum AVSubtitleType av_get_subtitle_fmt(const char *name)
+{
+ for (int i = 0; i < AV_SUBTITLE_FMT_NB; i++)
+ if (!strcmp(sub_fmt_info[i], name))
+ return i;
+ return AV_SUBTITLE_FMT_NONE;
+}
diff --git a/libavutil/subfmt.h b/libavutil/subfmt.h
index 791b45519f..3b8a0613b2 100644
--- a/libavutil/subfmt.h
+++ b/libavutil/subfmt.h
@@ -21,6 +21,9 @@
#ifndef AVUTIL_SUBFMT_H
#define AVUTIL_SUBFMT_H
+#include <stdint.h>
+
+#include "buffer.h"
#include "version.h"
enum AVSubtitleType {
@@ -65,4 +68,48 @@ enum AVSubtitleType {
AV_SUBTITLE_FMT_NB, ///< number of subtitle formats, DO NOT USE THIS if you want to link with shared libav* because the number of formats might differ between versions.
};
+typedef struct AVSubtitleArea {
+#define AV_NUM_BUFFER_POINTERS 1
+
+ enum AVSubtitleType type;
+ int flags;
+
+ int x; ///< top left corner of area.
+ int y; ///< top left corner of area.
+ int w; ///< width of area.
+ int h; ///< height of area.
+ int nb_colors; ///< number of colors in bitmap palette (@ref pal).
+
+ /**
+ * Buffers and line sizes for the bitmap of this subtitle.
+ *
+ * @{
+ */
+ AVBufferRef *buf[AV_NUM_BUFFER_POINTERS];
+ int linesize[AV_NUM_BUFFER_POINTERS];
+ /**
+ * @}
+ */
+
+ uint32_t pal[256]; ///< RGBA palette for the bitmap.
+
+ char *text; ///< 0-terminated plain UTF-8 text
+ char *ass; ///< 0-terminated ASS/SSA compatible event line.
+
+} AVSubtitleArea;
+
+/**
+ * Return the name of sub_fmt, or NULL if sub_fmt is not
+ * recognized.
+ */
+const char *av_get_subtitle_fmt_name(enum AVSubtitleType sub_fmt);
+
+/**
+ * Return a subtitle format corresponding to name, or AV_SUBTITLE_FMT_NONE
+ * on error.
+ *
+ * @param name Subtitle format name.
+ */
+enum AVSubtitleType av_get_subtitle_fmt(const char *name);
+
#endif /* AVUTIL_SUBFMT_H */
--
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