lavc: add lavfi metadata support.

This commit introduces a new AVPacket side data type:
AV_PKT_DATA_STRINGS_METADATA. Its main goal is to provide a way to
transmit the metadata from the AVFilterBufferRef up to the AVFrame. This
is at the moment "only" useful for lavfi input from libavdevice:
lavd/lavfi only outputs packets, and the metadata from the buffer ref
kept in its context needs to be transmitted from the packet to the frame
by the decoders. The buffer ref can be destroyed at any time (along with
the metadata), and a duplication of the AVPacket needs to duplicate the
metadata as well, so the choice of using the side data to store them was
selected.

Making sure lavd/lavfi raises the metadata is useful to allow tools like
ffprobe to access the filters metadata (it is at the moment the only
way); ffprobe will now automatically show the AVFrame metadata in any
customizable output format for users. API users will also be able to
access the AVFrame->metadata pointer the same way ffprobe does
(av_frame_get_metadata).

All the changes are done in this single commit to avoid some memory
leaks: for instances, the changes in lavfi/avcodec.c are meant to
duplicate the metadata from the buffer ref into the AVFrame. Unless we
have an internal way of freeing the AVFrame->metadata automatically, it
will leak in most of the user apps. To fix this problem, we introduce
AVCodecContext->metadata and link avctx->metadata to the current
frame->metadata and free it at each decode frame call (and in the codec
closing callback for the last one). But doing this also means to update
the way the tiff decoder already handles the AVFrame->metadata (it's the
only one decoder with frame metadata at the moment), by making sure it
is not trying to free a pointer already freed by the lavc internals.

The lavfi/avcodec.c buffer ref code is based on an old Thomas Kühnel
work, the rest of the code belongs to the commit author.

Signed-off-by: Thomas Kühnel <kuehnelth@googlemail.com>
Signed-off-by: Clément Bœsch <ubitux@gmail.com>

diff --git a/doc/APIchanges b/doc/APIchanges
index 1d6d34b500cadd6d2074ffb7f1f4d174947b53d9..bb9d543b92768b4e039368b29af52f2ce2df2a6d 100644 (file)
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -15,6 +15,13 @@ libavutil:     2011-04-18
 
 API changes, most recent first:
 
+2012-10-21 - xxxxxxx - lavc  54.68.100 - avcodec.h
+                       lavfi  3.20.100 - avfilter.h
+  Add AV_PKT_DATA_STRINGS_METADATA side data type, used to transmit key/value
+  strings between AVPacket and AVFrame, and add metadata field to
+  AVCodecContext (which shall not be accessed by users; see AVFrame metadata
+  instead).
+
 2012-09-27 - a70b493 - lavd 54.3.100 - version.h
   Add LIBAVDEVICE_IDENT symbol.
 

diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 0b3a19af1936ef718e123b958562502cf3cdfd38..3936d5e1c0292949400bfcfcc4aec8f6231aa469 100644 (file)
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -942,6 +942,12 @@ enum AVPacketSideDataType {
      * @endcode
      */
     AV_PKT_DATA_JP_DUALMONO,
+
+    /**
+     * A list of zero terminated key/value strings. There is no end marker for
+     * the list, so it is required to rely on the side data size to stop.
+     */
+    AV_PKT_DATA_STRINGS_METADATA,
 };
 
 typedef struct AVPacket {
@@ -3091,6 +3097,13 @@ typedef struct AVCodecContext {
     int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
     int64_t pts_correction_last_pts;       /// PTS of the last frame
     int64_t pts_correction_last_dts;       /// DTS of the last frame
+
+    /**
+     * Current frame metadata.
+     * - decoding: maintained and used by libavcodec, not intended to be used by user apps
+     * - encoding: unused
+     */
+    AVDictionary *metadata;
 } AVCodecContext;
 
 AVRational av_codec_get_pkt_timebase         (const AVCodecContext *avctx);

diff --git a/libavcodec/tiff.c b/libavcodec/tiff.c
index 1f9a0295564d8ff060ca2350fc40a1770ca52884..34dd42dbf053598ef09b78e0651e1e4541ab45f8 100644 (file)
--- a/libavcodec/tiff.c
+++ b/libavcodec/tiff.c
@@ -1018,8 +1018,9 @@ static int decode_frame(AVCodecContext *avctx,
     s->compr = TIFF_RAW;
     s->fill_order = 0;
     free_geotags(s);
-    /* free existing metadata */
-    av_dict_free(&s->picture.metadata);
+    /* metadata has been destroyed from lavc internals, that pointer is not
+     * valid anymore */
+    s->picture.metadata = NULL;
 
     // As TIFF 6.0 specification puts it "An arbitrary but carefully chosen number
     // that further identifies the file as a TIFF file"
@@ -1169,8 +1170,6 @@ static av_cold int tiff_end(AVCodecContext *avctx)
     TiffContext *const s = avctx->priv_data;
 
     free_geotags(s);
-    if (avctx->coded_frame && avctx->coded_frame->metadata)
-        av_dict_free(&avctx->coded_frame->metadata);
 
     ff_lzw_decode_close(&s->lzw);
     if (s->picture.data[0])

diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index e4b3ed71c6b4a8b52510d7443b90fad89491d375..06999f5425cba89768dc3e904089be32f76f3c95 100644 (file)
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -1592,6 +1592,31 @@ static void apply_param_change(AVCodecContext *avctx, AVPacket *avpkt)
     }
 }
 
+static int add_metadata_from_side_data(AVCodecContext *avctx, AVFrame *frame)
+{
+    int size, ret = 0;
+    const uint8_t *side_metadata;
+    const uint8_t *end;
+
+    av_dict_free(&avctx->metadata);
+    side_metadata = av_packet_get_side_data(avctx->pkt,
+                                            AV_PKT_DATA_STRINGS_METADATA, &size);
+    if (!side_metadata)
+        goto end;
+    end = side_metadata + size;
+    while (side_metadata < end) {
+        const uint8_t *key = side_metadata;
+        const uint8_t *val = side_metadata + strlen(key) + 1;
+        int ret = av_dict_set(&frame->metadata, key, val, 0);
+        if (ret < 0)
+            break;
+        side_metadata = val + strlen(val) + 1;
+    }
+end:
+    avctx->metadata = frame->metadata;
+    return ret;
+}
+
 int attribute_align_arg avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
                                               int *got_picture_ptr,
                                               const AVPacket *avpkt)
@@ -1630,6 +1655,7 @@ int attribute_align_arg avcodec_decode_video2(AVCodecContext *avctx, AVFrame *pi
             if (!picture->height)                  picture->height              = avctx->height;
             if (picture->format == AV_PIX_FMT_NONE)   picture->format              = avctx->pix_fmt;
         }
+        add_metadata_from_side_data(avctx, picture);
 
         emms_c(); //needed to avoid an emms_c() call before every return;
 
@@ -1749,6 +1775,7 @@ int attribute_align_arg avcodec_decode_audio4(AVCodecContext *avctx,
             if (!frame->sample_rate)
                 frame->sample_rate = avctx->sample_rate;
         }
+        add_metadata_from_side_data(avctx, frame);
 
         side= av_packet_get_side_data(avctx->pkt, AV_PKT_DATA_SKIP_SAMPLES, &side_size);
         if(side && side_size>=10) {
@@ -1901,6 +1928,7 @@ av_cold int avcodec_close(AVCodecContext *avctx)
         avctx->internal->byte_buffer_size = 0;
         av_freep(&avctx->internal->byte_buffer);
         av_freep(&avctx->internal);
+        av_dict_free(&avctx->metadata);
     }
 
     if (avctx->priv_data && avctx->codec && avctx->codec->priv_class)

diff --git a/libavcodec/version.h b/libavcodec/version.h
index b2d5c1b506dc85694168ef6d8031db2b2d583bf1..a52d72668b1ba95f74e44fc5b59757ca9cdcc445 100644 (file)
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -29,7 +29,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVCODEC_VERSION_MAJOR 54
-#define LIBAVCODEC_VERSION_MINOR 67
+#define LIBAVCODEC_VERSION_MINOR 68
 #define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \

diff --git a/libavdevice/lavfi.c b/libavdevice/lavfi.c
index 944794fb87451261998337e068edc54d777915a5..82c5844fab41f76a19e6d4de8dbf815baea99d94 100644 (file)
--- a/libavdevice/lavfi.c
+++ b/libavdevice/lavfi.c
@@ -27,6 +27,7 @@
 
 #include "float.h"              /* DBL_MIN, DBL_MAX */
 
+#include "libavutil/bprint.h"
 #include "libavutil/log.h"
 #include "libavutil/mem.h"
 #include "libavutil/opt.h"
@@ -339,6 +340,28 @@ static int lavfi_read_packet(AVFormatContext *avctx, AVPacket *pkt)
         memcpy(pkt->data, ref->data[0], size);
     }
 
+    if (ref->metadata) {
+        uint8_t *metadata;
+        AVDictionaryEntry *e = NULL;
+        AVBPrint meta_buf;
+
+        av_bprint_init(&meta_buf, 0, AV_BPRINT_SIZE_UNLIMITED);
+        while ((e = av_dict_get(ref->metadata, "", e, AV_DICT_IGNORE_SUFFIX))) {
+            av_bprintf(&meta_buf, "%s", e->key);
+            av_bprint_chars(&meta_buf, '\0', 1);
+            av_bprintf(&meta_buf, "%s", e->value);
+            av_bprint_chars(&meta_buf, '\0', 1);
+        }
+        if (!av_bprint_is_complete(&meta_buf) ||
+            !(metadata = av_packet_new_side_data(pkt, AV_PKT_DATA_STRINGS_METADATA,
+                                                 meta_buf.len))) {
+            av_bprint_finalize(&meta_buf, NULL);
+            return AVERROR(ENOMEM);
+        }
+        memcpy(metadata, meta_buf.str, meta_buf.len);
+        av_bprint_finalize(&meta_buf, NULL);
+    }
+
     pkt->stream_index = stream_idx;
     pkt->pts = ref->pts;
     pkt->pos = ref->pos;

diff --git a/libavfilter/avcodec.c b/libavfilter/avcodec.c
index 313080dc01b518e410ca36754b566ad7b25b4eef..2a173b2c91f288309b3ca35b6c6b0b92dfd5a2d0 100644 (file)
--- a/libavfilter/avcodec.c
+++ b/libavfilter/avcodec.c
@@ -33,6 +33,9 @@ int avfilter_copy_frame_props(AVFilterBufferRef *dst, const AVFrame *src)
     dst->pos    = av_frame_get_pkt_pos(src);
     dst->format = src->format;
 
+    av_dict_free(&dst->metadata);
+    av_dict_copy(&dst->metadata, av_frame_get_metadata(src), 0);
+
     switch (dst->type) {
     case AVMEDIA_TYPE_VIDEO:
         dst->video->w                   = src->width;

diff --git a/libavfilter/avfilter.h b/libavfilter/avfilter.h
index 510f28a8deba7eb76760733c0136e513d5ba725d..dccd4204f309680120ab503bfe244dc673eee43b 100644 (file)
--- a/libavfilter/avfilter.h
+++ b/libavfilter/avfilter.h
@@ -180,6 +180,8 @@ typedef struct AVFilterBufferRef {
     int perms;                  ///< permissions, see the AV_PERM_* flags
 
     enum AVMediaType type;      ///< media type of buffer data
+
+    AVDictionary *metadata;     ///< dictionary containing metadata key=value tags
 } AVFilterBufferRef;
 
 /**

diff --git a/libavfilter/buffer.c b/libavfilter/buffer.c
index fc65b828259effab42ff7740cbf425741fc8f66a..ae1867f8348886664c242cc47c88bed640b0fa69 100644 (file)
--- a/libavfilter/buffer.c
+++ b/libavfilter/buffer.c
@@ -54,6 +54,10 @@ AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask)
     if (!ret)
         return NULL;
     *ret = *ref;
+
+    ret->metadata = NULL;
+    av_dict_copy(&ret->metadata, ref->metadata, 0);
+
     if (ref->type == AVMEDIA_TYPE_VIDEO) {
         ret->video = av_malloc(sizeof(AVFilterBufferRefVideoProps));
         if (!ret->video) {
@@ -172,6 +176,7 @@ void avfilter_unref_buffer(AVFilterBufferRef *ref)
         av_freep(&ref->video->qp_table);
     av_freep(&ref->video);
     av_freep(&ref->audio);
+    av_dict_free(&ref->metadata);
     av_free(ref);
 }
 
@@ -197,6 +202,9 @@ void avfilter_copy_buffer_ref_props(AVFilterBufferRef *dst, AVFilterBufferRef *s
     case AVMEDIA_TYPE_AUDIO: *dst->audio = *src->audio; break;
     default: break;
     }
+
+    av_dict_free(&dst->metadata);
+    av_dict_copy(&dst->metadata, src->metadata, 0);
 }
 
 AVFilterBufferRef *ff_copy_buffer_ref(AVFilterLink *outlink,

diff --git a/libavfilter/version.h b/libavfilter/version.h
index 1f9320c5e5adc4ad52af8dc14956f6dabaa64be9..eeb78059e7a3acdac4eaba725880460a3797a4e0 100644 (file)
--- a/libavfilter/version.h
+++ b/libavfilter/version.h
@@ -29,8 +29,8 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  3
-#define LIBAVFILTER_VERSION_MINOR  19
-#define LIBAVFILTER_VERSION_MICRO 103
+#define LIBAVFILTER_VERSION_MINOR  20
+#define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
                                                LIBAVFILTER_VERSION_MINOR, \