lavf: use the new bitstream filter for extracting extradata

This also fixes a minor bug introduced in the codecpar conversion, where
the termination condition for extracting the extradata does not match
the actual extradata setting code. As a result, the packet durations
made up by lavf go back to their values before the codecpar conversion.
That is of little consequence since that code should eventually be
dropped completely.

2 files changed, 119 insertions, 13 deletions

diff --git a/libavformat/internal.h b/libavformat/internal.h
index de55af5af4..52cd29b9b7 100644
--- a/libavformat/internal.h
+++ b/libavformat/internal.h
@@ -113,6 +113,15 @@ struct AVStreamInternal {
 
     enum AVCodecID orig_codec_id;
 
+    /* the context for extracting extradata in find_stream_info()
+     * inited=1/bsf=NULL signals that extracting is not possible (codec not
+     * supported) */
+    struct {
+        AVBSFContext *bsf;
+        AVPacket     *pkt;
+        int inited;
+    } extract_extradata;
+
 #if FF_API_LAVF_AVCTX
     // whether the deprecated stream codec context needs
     // to be filled from the codec parameters
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 0e94b15b72..1c93326ab2 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -2089,6 +2089,104 @@ static int get_std_framerate(int i)
         return ((const int[]) { 24, 30, 60, 12, 15 })[i - 60 * 12] * 1000 * 12;
 }
 
+static int extract_extradata_init(AVStream *st)
+{
+    AVStreamInternal *i = st->internal;
+    const AVBitStreamFilter *f;
+    int ret;
+
+    f = av_bsf_get_by_name("extract_extradata");
+    if (!f)
+        goto finish;
+
+    i->extract_extradata.pkt = av_packet_alloc();
+    if (!i->extract_extradata.pkt)
+        return AVERROR(ENOMEM);
+
+    ret = av_bsf_alloc(f, &i->extract_extradata.bsf);
+    if (ret < 0)
+        goto fail;
+
+    ret = avcodec_parameters_copy(i->extract_extradata.bsf->par_in,
+                                  st->codecpar);
+    if (ret < 0)
+        goto fail;
+
+    i->extract_extradata.bsf->time_base_in = st->time_base;
+
+    /* if init fails here, we assume extracting extradata is just not
+     * supported for this codec, so we return success */
+    ret = av_bsf_init(i->extract_extradata.bsf);
+    if (ret < 0) {
+        av_bsf_free(&i->extract_extradata.bsf);
+        ret = 0;
+    }
+
+finish:
+    i->extract_extradata.inited = 1;
+
+    return 0;
+fail:
+    av_bsf_free(&i->extract_extradata.bsf);
+    av_packet_free(&i->extract_extradata.pkt);
+    return ret;
+}
+
+static int extract_extradata(AVStream *st, AVPacket *pkt)
+{
+    AVStreamInternal *i = st->internal;
+    AVPacket *pkt_ref;
+    int ret;
+
+    if (!i->extract_extradata.inited) {
+        ret = extract_extradata_init(st);
+        if (ret < 0)
+            return ret;
+    }
+
+    if (i->extract_extradata.inited && !i->extract_extradata.bsf)
+        return 0;
+
+    pkt_ref = i->extract_extradata.pkt;
+    ret = av_packet_ref(pkt_ref, pkt);
+    if (ret < 0)
+        return ret;
+
+    ret = av_bsf_send_packet(i->extract_extradata.bsf, pkt_ref);
+    if (ret < 0) {
+        av_packet_unref(pkt_ref);
+        return ret;
+    }
+
+    while (ret >= 0 && !i->avctx->extradata) {
+        int extradata_size;
+        uint8_t *extradata;
+
+        ret = av_bsf_receive_packet(i->extract_extradata.bsf, pkt_ref);
+        if (ret < 0) {
+            if (ret != AVERROR(EAGAIN) && ret != AVERROR_EOF)
+                return ret;
+            continue;
+        }
+
+        extradata = av_packet_get_side_data(pkt_ref, AV_PKT_DATA_NEW_EXTRADATA,
+                                            &extradata_size);
+
+        if (extradata) {
+            i->avctx->extradata = av_mallocz(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
+            if (!i->avctx->extradata) {
+                av_packet_unref(pkt_ref);
+                return AVERROR(ENOMEM);
+            }
+            memcpy(i->avctx->extradata, extradata, extradata_size);
+            i->avctx->extradata_size = extradata_size;
+        }
+        av_packet_unref(pkt_ref);
+    }
+
+    return 0;
+}
+
 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
 {
     int i, count, ret, read_size, j;
@@ -2194,8 +2292,10 @@ FF_ENABLE_DEPRECATION_WARNINGS
                 st->codec_info_nb_frames < fps_analyze_framecount &&
                 st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO)
                 break;
-            if (st->parser && st->parser->parser->split &&
-                !st->codecpar->extradata)
+            if (!st->codecpar->extradata &&
+                !st->internal->avctx->extradata &&
+                (!st->internal->extract_extradata.inited ||
+                 st->internal->extract_extradata.bsf))
                 break;
             if (st->first_dts == AV_NOPTS_VALUE &&
                 st->codec_info_nb_frames < ic->max_ts_probe &&
@@ -2331,17 +2431,10 @@ FF_ENABLE_DEPRECATION_WARNINGS
                 break;
             }
         }
-        if (st->parser && st->parser->parser->split && !avctx->extradata) {
-            int i = st->parser->parser->split(avctx, pkt->data, pkt->size);
-            if (i > 0 && i < FF_MAX_EXTRADATA_SIZE) {
-                avctx->extradata_size = i;
-                avctx->extradata      = av_mallocz(avctx->extradata_size +
-                                                   AV_INPUT_BUFFER_PADDING_SIZE);
-                if (!avctx->extradata)
-                    return AVERROR(ENOMEM);
-                memcpy(avctx->extradata, pkt->data,
-                       avctx->extradata_size);
-            }
+        if (!st->internal->avctx->extradata) {
+            ret = extract_extradata(st, pkt);
+            if (ret < 0)
+                goto find_stream_info_err;
         }
 
         /* If still no information, we try to open the codec and to
@@ -2468,6 +2561,8 @@ FF_ENABLE_DEPRECATION_WARNINGS
 find_stream_info_err:
     for (i = 0; i < ic->nb_streams; i++) {
         av_freep(&ic->streams[i]->info);
+        av_bsf_free(&ic->streams[i]->internal->extract_extradata.bsf);
+        av_packet_free(&ic->streams[i]->internal->extract_extradata.pkt);
     }
     return ret;
 }
@@ -2575,6 +2670,8 @@ static void free_stream(AVStream **pst)
 
     if (st->internal) {
         avcodec_free_context(&st->internal->avctx);
+        av_bsf_free(&st->internal->extract_extradata.bsf);
+        av_packet_free(&st->internal->extract_extradata.pkt);
     }
     av_freep(&st->internal);