diff --git a/libavformat/asfdec.c b/libavformat/asfdec.c
index c7d03f01f3..1b77f02ab4 100644
--- a/libavformat/asfdec.c
+++ b/libavformat/asfdec.c
@@ -909,7 +909,7 @@ static int asf_get_packet(AVFormatContext *s, AVIOContext *pb)
     if (asf->no_resync_search)
         off = 3;
     else if (s->packet_size > 0)
-        off = (avio_tell(pb) - s->data_offset) % s->packet_size + 3;
+        off = (avio_tell(pb) - s->internal->data_offset) % s->packet_size + 3;
 
     c = d = e = -1;
     while (off-- > 0) {
@@ -1445,9 +1445,9 @@ static int64_t asf_read_pts(AVFormatContext *s, int stream_index,
         start_pos[i] = pos;
 
     if (s->packet_size > 0)
-        pos = (pos + s->packet_size - 1 - s->data_offset) /
+        pos = (pos + s->packet_size - 1 - s->internal->data_offset) /
               s->packet_size * s->packet_size +
-              s->data_offset;
+              s->internal->data_offset;
     *ppos = pos;
     if (avio_seek(s->pb, pos, SEEK_SET) < 0)
         return AV_NOPTS_VALUE;
@@ -1526,7 +1526,7 @@ static int asf_build_simple_index(AVFormatContext *s, int stream_index)
         for (i = 0; i < ict; i++) {
             int pktnum        = avio_rl32(s->pb);
             int pktct         = avio_rl16(s->pb);
-            int64_t pos       = s->data_offset + s->packet_size * (int64_t)pktnum;
+            int64_t pos       = s->internal->data_offset + s->packet_size * (int64_t)pktnum;
             int64_t index_pts = FFMAX(av_rescale(itime, i, 10000) - asf->hdr.preroll, 0);
 
             if (pos != last_pos) {
@@ -1569,7 +1569,7 @@ static int asf_read_seek(AVFormatContext *s, int stream_index,
     /* explicitly handle the case of seeking to 0 */
     if (!pts) {
         asf_reset_header(s);
-        avio_seek(s->pb, s->data_offset, SEEK_SET);
+        avio_seek(s->pb, s->internal->data_offset, SEEK_SET);
         return 0;
     }
 
diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index db72c1801b..3007f814ce 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -1503,7 +1503,6 @@ typedef struct AVFormatContext {
 #define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative
 #define AVFMT_AVOID_NEG_TS_MAKE_ZERO         2 ///< Shift timestamps so that they start at 0
 
-
     /**
      * Transport stream id.
      * This will be moved into demuxer private options. Thus no API/ABI compatibility
@@ -1617,56 +1616,6 @@ typedef struct AVFormatContext {
      */
     char *format_whitelist;
 
-    /*****************************************************************
-     * All fields below this line are not part of the public API. They
-     * may not be used outside of libavformat and can be changed and
-     * removed at will.
-     * New public fields should be added right above.
-     *****************************************************************
-     */
-
-    /**
-     * This buffer is only needed when packets were already buffered but
-     * not decoded, for example to get the codec parameters in MPEG
-     * streams.
-     */
-    struct AVPacketList *packet_buffer;
-    struct AVPacketList *packet_buffer_end;
-
-    /* av_seek_frame() support */
-    int64_t data_offset; /**< offset of the first packet */
-
-    /**
-     * Raw packets from the demuxer, prior to parsing and decoding.
-     * This buffer is used for buffering packets until the codec can
-     * be identified, as parsing cannot be done without knowing the
-     * codec.
-     */
-    struct AVPacketList *raw_packet_buffer;
-    struct AVPacketList *raw_packet_buffer_end;
-    /**
-     * Packets split by the parser get queued here.
-     */
-    struct AVPacketList *parse_queue;
-    struct AVPacketList *parse_queue_end;
-    /**
-     * Remaining size available for raw_packet_buffer, in bytes.
-     */
-#define RAW_PACKET_BUFFER_SIZE 2500000
-    int raw_packet_buffer_remaining_size;
-
-    /**
-     * Offset to remap timestamps to be non-negative.
-     * Expressed in timebase units.
-     * @see AVStream.mux_ts_offset
-     */
-    int64_t offset;
-
-    /**
-     * Timebase for the timestamp offset.
-     */
-    AVRational offset_timebase;
-
     /**
      * An opaque field for libavformat internal usage.
      * Must not be accessed in any way by callers.
diff --git a/libavformat/boadec.c b/libavformat/boadec.c
index 45f6b3976b..be003e59c1 100644
--- a/libavformat/boadec.c
+++ b/libavformat/boadec.c
@@ -21,6 +21,7 @@
 
 #include "libavutil/intreadwrite.h"
 #include "avformat.h"
+#include "internal.h"
 
 static int probe(AVProbeData *p)
 {
@@ -52,11 +53,11 @@ static int read_header(AVFormatContext *s)
     avio_rl32(s->pb);
     st->codec->sample_rate = avio_rl32(s->pb);
     st->codec->channels    = avio_rl32(s->pb);
-    s->data_offset         = avio_rl32(s->pb);
+    s->internal->data_offset = avio_rl32(s->pb);
     avio_r8(s->pb);
     st->codec->block_align = st->codec->channels * avio_rl32(s->pb);
 
-    avio_seek(s->pb, s->data_offset, SEEK_SET);
+    avio_seek(s->pb, s->internal->data_offset, SEEK_SET);
 
     return 0;
 }
diff --git a/libavformat/dv.c b/libavformat/dv.c
index 3243ca2ece..485a5f8742 100644
--- a/libavformat/dv.c
+++ b/libavformat/dv.c
@@ -425,7 +425,7 @@ static int64_t dv_frame_offset(AVFormatContext *s, DVDemuxContext *c,
     const AVDVProfile *sys = av_dv_codec_profile2(c->vst->codec->width, c->vst->codec->height,
                                                  c->vst->codec->pix_fmt, c->vst->codec->time_base);
     int64_t offset;
-    int64_t size       = avio_size(s->pb) - s->data_offset;
+    int64_t size       = avio_size(s->pb) - s->internal->data_offset;
     int64_t max_offset = ((size - 1) / sys->frame_size) * sys->frame_size;
 
     offset = sys->frame_size * timestamp;
@@ -435,7 +435,7 @@ static int64_t dv_frame_offset(AVFormatContext *s, DVDemuxContext *c,
     else if (offset < 0)
         offset = 0;
 
-    return offset + s->data_offset;
+    return offset + s->internal->data_offset;
 }
 
 void ff_dv_offset_reset(DVDemuxContext *c, int64_t frame_offset)
diff --git a/libavformat/internal.h b/libavformat/internal.h
index d397bc4f55..76ffcc517e 100644
--- a/libavformat/internal.h
+++ b/libavformat/internal.h
@@ -54,6 +54,48 @@ struct AVFormatInternal {
      */
     int nb_interleaved_streams;
 
+    /**
+     * This buffer is only needed when packets were already buffered but
+     * not decoded, for example to get the codec parameters in MPEG
+     * streams.
+     */
+    struct AVPacketList *packet_buffer;
+    struct AVPacketList *packet_buffer_end;
+
+    /* av_seek_frame() support */
+    int64_t data_offset; /**< offset of the first packet */
+
+    /**
+     * Raw packets from the demuxer, prior to parsing and decoding.
+     * This buffer is used for buffering packets until the codec can
+     * be identified, as parsing cannot be done without knowing the
+     * codec.
+     */
+    struct AVPacketList *raw_packet_buffer;
+    struct AVPacketList *raw_packet_buffer_end;
+    /**
+     * Packets split by the parser get queued here.
+     */
+    struct AVPacketList *parse_queue;
+    struct AVPacketList *parse_queue_end;
+    /**
+     * Remaining size available for raw_packet_buffer, in bytes.
+     */
+#define RAW_PACKET_BUFFER_SIZE 2500000
+    int raw_packet_buffer_remaining_size;
+
+    /**
+     * Offset to remap timestamps to be non-negative.
+     * Expressed in timebase units.
+     * @see AVStream.mux_ts_offset
+     */
+    int64_t offset;
+
+    /**
+     * Timebase for the timestamp offset.
+     */
+    AVRational offset_timebase;
+
     int inject_global_side_data;
 };
 
diff --git a/libavformat/mp3dec.c b/libavformat/mp3dec.c
index 519d046211..480cffedad 100644
--- a/libavformat/mp3dec.c
+++ b/libavformat/mp3dec.c
@@ -423,18 +423,18 @@ static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp,
 
     if (   mp3->is_cbr
         && st->duration > 0
-        && mp3->header_filesize > s->data_offset
+        && mp3->header_filesize > s->internal->data_offset
         && mp3->frames) {
         int64_t filesize = avio_size(s->pb);
         int64_t duration;
-        if (filesize <= s->data_offset)
+        if (filesize <= s->internal->data_offset)
             filesize = mp3->header_filesize;
-        filesize -= s->data_offset;
-        duration = av_rescale(st->duration, filesize, mp3->header_filesize - s->data_offset);
+        filesize -= s->internal->data_offset;
+        duration = av_rescale(st->duration, filesize, mp3->header_filesize - s->internal->data_offset);
         ie = &ie1;
         timestamp = av_clip64(timestamp, 0, duration);
         ie->timestamp = timestamp;
-        ie->pos       = av_rescale(timestamp, filesize, duration) + s->data_offset;
+        ie->pos       = av_rescale(timestamp, filesize, duration) + s->internal->data_offset;
     } else if (mp3->xing_toc) {
         if (ret < 0)
             return ret;
diff --git a/libavformat/mtv.c b/libavformat/mtv.c
index addad24440..a91e4c8649 100644
--- a/libavformat/mtv.c
+++ b/libavformat/mtv.c
@@ -200,7 +200,7 @@ static int mtv_read_packet(AVFormatContext *s, AVPacket *pkt)
     AVIOContext *pb = s->pb;
     int ret;
 
-    if((avio_tell(pb) - s->data_offset + mtv->img_segment_size) % mtv->full_segment_size)
+    if((avio_tell(pb) - s->internal->data_offset + mtv->img_segment_size) % mtv->full_segment_size)
     {
         avio_skip(pb, MTV_AUDIO_PADDING_SIZE);
 
diff --git a/libavformat/mux.c b/libavformat/mux.c
index 050c4d9411..72d8e942d5 100644
--- a/libavformat/mux.c
+++ b/libavformat/mux.c
@@ -555,16 +555,16 @@ static int write_packet(AVFormatContext *s, AVPacket *pkt)
         AVStream *st = s->streams[pkt->stream_index];
         int64_t offset = st->mux_ts_offset;
 
-        if (s->offset == AV_NOPTS_VALUE && pkt->dts != AV_NOPTS_VALUE &&
+        if (s->internal->offset == AV_NOPTS_VALUE && pkt->dts != AV_NOPTS_VALUE &&
             (pkt->dts < 0 || s->avoid_negative_ts == AVFMT_AVOID_NEG_TS_MAKE_ZERO)) {
-            s->offset = -pkt->dts;
-            s->offset_timebase = st->time_base;
+            s->internal->offset = -pkt->dts;
+            s->internal->offset_timebase = st->time_base;
         }
 
-        if (s->offset != AV_NOPTS_VALUE && !offset) {
+        if (s->internal->offset != AV_NOPTS_VALUE && !offset) {
             offset = st->mux_ts_offset =
-                av_rescale_q_rnd(s->offset,
-                                 s->offset_timebase,
+                av_rescale_q_rnd(s->internal->offset,
+                                 s->internal->offset_timebase,
                                  st->time_base,
                                  AV_ROUND_UP);
         }
@@ -694,7 +694,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
     if (s->streams[pkt->stream_index]->last_in_packet_buffer) {
         next_point = &(st->last_in_packet_buffer->next);
     } else {
-        next_point = &s->packet_buffer;
+        next_point = &s->internal->packet_buffer;
     }
 
     if (chunked) {
@@ -718,7 +718,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
         if (chunked && !(this_pktl->pkt.flags & CHUNK_START))
             goto next_non_null;
 
-        if (compare(s, &s->packet_buffer_end->pkt, pkt)) {
+        if (compare(s, &s->internal->packet_buffer_end->pkt, pkt)) {
             while (   *next_point
                    && ((chunked && !((*next_point)->pkt.flags&CHUNK_START))
                        || !compare(s, &(*next_point)->pkt, pkt)))
@@ -726,12 +726,12 @@ FF_ENABLE_DEPRECATION_WARNINGS
             if (*next_point)
                 goto next_non_null;
         } else {
-            next_point = &(s->packet_buffer_end->next);
+            next_point = &(s->internal->packet_buffer_end->next);
         }
     }
     av_assert1(!*next_point);
 
-    s->packet_buffer_end = this_pktl;
+    s->internal->packet_buffer_end = this_pktl;
 next_non_null:
 
     this_pktl->next = *next_point;
@@ -792,11 +792,11 @@ int ff_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out,
         flush = 1;
 
     if (s->max_interleave_delta > 0 &&
-        s->packet_buffer &&
+        s->internal->packet_buffer &&
         !flush &&
         s->internal->nb_interleaved_streams == stream_count+noninterleaved_count
     ) {
-        AVPacket *top_pkt = &s->packet_buffer->pkt;
+        AVPacket *top_pkt = &s->internal->packet_buffer->pkt;
         int64_t delta_dts = INT64_MIN;
         int64_t top_dts = av_rescale_q(top_pkt->dts,
                                        s->streams[top_pkt->stream_index]->time_base,
@@ -826,13 +826,13 @@ int ff_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out,
 
     if (stream_count && flush) {
         AVStream *st;
-        pktl = s->packet_buffer;
+        pktl = s->internal->packet_buffer;
         *out = pktl->pkt;
         st   = s->streams[out->stream_index];
 
-        s->packet_buffer = pktl->next;
-        if (!s->packet_buffer)
-            s->packet_buffer_end = NULL;
+        s->internal->packet_buffer = pktl->next;
+        if (!s->internal->packet_buffer)
+            s->internal->packet_buffer_end = NULL;
 
         if (st->last_in_packet_buffer == pktl)
             st->last_in_packet_buffer = NULL;
diff --git a/libavformat/mxfenc.c b/libavformat/mxfenc.c
index a22974e1b4..17ad132865 100644
--- a/libavformat/mxfenc.c
+++ b/libavformat/mxfenc.c
@@ -2322,7 +2322,7 @@ static int mxf_interleave_get_packet(AVFormatContext *s, AVPacket *out, AVPacket
         stream_count += !!s->streams[i]->last_in_packet_buffer;
 
     if (stream_count && (s->nb_streams == stream_count || flush)) {
-        AVPacketList *pktl = s->packet_buffer;
+        AVPacketList *pktl = s->internal->packet_buffer;
         if (s->nb_streams != stream_count) {
             AVPacketList *last = NULL;
             // find last packet in edit unit
@@ -2346,20 +2346,20 @@ static int mxf_interleave_get_packet(AVFormatContext *s, AVPacket *out, AVPacket
             if (last)
                 last->next = NULL;
             else {
-                s->packet_buffer = NULL;
-                s->packet_buffer_end= NULL;
+                s->internal->packet_buffer = NULL;
+                s->internal->packet_buffer_end= NULL;
                 goto out;
             }
-            pktl = s->packet_buffer;
+            pktl = s->internal->packet_buffer;
         }
 
         *out = pktl->pkt;
         av_dlog(s, "out st:%d dts:%"PRId64"\n", (*out).stream_index, (*out).dts);
-        s->packet_buffer = pktl->next;
+        s->internal->packet_buffer = pktl->next;
         if(s->streams[pktl->pkt.stream_index]->last_in_packet_buffer == pktl)
             s->streams[pktl->pkt.stream_index]->last_in_packet_buffer= NULL;
-        if(!s->packet_buffer)
-            s->packet_buffer_end= NULL;
+        if(!s->internal->packet_buffer)
+            s->internal->packet_buffer_end= NULL;
         av_freep(&pktl);
         return 1;
     } else {
diff --git a/libavformat/nutdec.c b/libavformat/nutdec.c
index ef29bdf79c..00e86bb50b 100644
--- a/libavformat/nutdec.c
+++ b/libavformat/nutdec.c
@@ -790,7 +790,7 @@ static int nut_read_header(AVFormatContext *s)
         decode_info_header(nut);
     }
 
-    s->data_offset = pos - 8;
+    s->internal->data_offset = pos - 8;
 
     if (bc->seekable) {
         int64_t orig_pos = avio_tell(bc);
diff --git a/libavformat/oggdec.c b/libavformat/oggdec.c
index 8f146e49fe..3f152a4434 100644
--- a/libavformat/oggdec.c
+++ b/libavformat/oggdec.c
@@ -142,7 +142,7 @@ static int ogg_reset(AVFormatContext *s)
         os->segp       = 0;
         os->incomplete = 0;
         os->got_data = 0;
-        if (start_pos <= s->data_offset) {
+        if (start_pos <= s->internal->data_offset) {
             os->lastpts = 0;
         }
         os->end_trimming = 0;
@@ -520,8 +520,8 @@ static int ogg_packet(AVFormatContext *s, int *sid, int *dstart, int *dsize,
 
             // Update the header state for all streams and
             // compute the data_offset.
-            if (!s->data_offset)
-                s->data_offset = os->sync_pos;
+            if (!s->internal->data_offset)
+                s->internal->data_offset = os->sync_pos;
 
             for (i = 0; i < ogg->nstreams; i++) {
                 struct ogg_stream *cur_os = ogg->streams + i;
@@ -529,7 +529,7 @@ static int ogg_packet(AVFormatContext *s, int *sid, int *dstart, int *dsize,
                 // if we have a partial non-header packet, its start is
                 // obviously at or after the data start
                 if (cur_os->incomplete)
-                    s->data_offset = FFMIN(s->data_offset, cur_os->sync_pos);
+                    s->internal->data_offset = FFMIN(s->internal->data_offset, cur_os->sync_pos);
             }
         } else {
             os->nb_header++;
@@ -613,7 +613,7 @@ static int ogg_get_length(AVFormatContext *s)
     ogg_restore(s, 0);
 
     ogg_save (s);
-    avio_seek (s->pb, s->data_offset, SEEK_SET);
+    avio_seek (s->pb, s->internal->data_offset, SEEK_SET);
     ogg_reset(s);
     while (streams_left > 0 && !ogg_packet(s, &i, NULL, NULL, NULL)) {
         int64_t pts;
diff --git a/libavformat/options.c b/libavformat/options.c
index 504404312c..22b922f89a 100644
--- a/libavformat/options.c
+++ b/libavformat/options.c
@@ -110,13 +110,13 @@ AVFormatContext *avformat_alloc_context(void)
     ic = av_malloc(sizeof(AVFormatContext));
     if (!ic) return ic;
     avformat_get_context_defaults(ic);
-    ic->offset = AV_NOPTS_VALUE;
 
     ic->internal = av_mallocz(sizeof(*ic->internal));
     if (!ic->internal) {
         avformat_free_context(ic);
         return NULL;
     }
+    ic->internal->offset = AV_NOPTS_VALUE;
 
     return ic;
 }
diff --git a/libavformat/pcm.c b/libavformat/pcm.c
index a57a4b6249..f62075fc82 100644
--- a/libavformat/pcm.c
+++ b/libavformat/pcm.c
@@ -21,6 +21,7 @@
 
 #include "libavutil/mathematics.h"
 #include "avformat.h"
+#include "internal.h"
 #include "pcm.h"
 
 #define RAW_SAMPLES     1024
@@ -68,7 +69,7 @@ int ff_pcm_read_seek(AVFormatContext *s,
 
     /* recompute exact position */
     st->cur_dts = av_rescale(pos, st->time_base.den, byte_rate * (int64_t)st->time_base.num);
-    if ((ret = avio_seek(s->pb, pos + s->data_offset, SEEK_SET)) < 0)
+    if ((ret = avio_seek(s->pb, pos + s->internal->data_offset, SEEK_SET)) < 0)
         return ret;
     return 0;
 }
diff --git a/libavformat/r3d.c b/libavformat/r3d.c
index 7a6f7a32f2..60e96bfbcd 100644
--- a/libavformat/r3d.c
+++ b/libavformat/r3d.c
@@ -185,8 +185,8 @@ static int r3d_read_header(AVFormatContext *s)
         return -1;
     }
 
-    s->data_offset = avio_tell(s->pb);
-    av_dlog(s, "data offset %#"PRIx64"\n", s->data_offset);
+    s->internal->data_offset = avio_tell(s->pb);
+    av_dlog(s, "data offset %#"PRIx64"\n", s->internal->data_offset);
     if (!s->pb->seekable)
         return 0;
     // find REOB/REOF/REOS to load index
@@ -212,7 +212,7 @@ static int r3d_read_header(AVFormatContext *s)
     }
 
  out:
-    avio_seek(s->pb, s->data_offset, SEEK_SET);
+    avio_seek(s->pb, s->internal->data_offset, SEEK_SET);
     return 0;
 }
 
diff --git a/libavformat/utils.c b/libavformat/utils.c
index aa96d15674..917f8ceaf0 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -319,8 +319,8 @@ int av_demuxer_open(AVFormatContext *ic) {
             return err;
     }
 
-    if (ic->pb && !ic->data_offset)
-        ic->data_offset = avio_tell(ic->pb);
+    if (ic->pb && !ic->internal->data_offset)
+        ic->internal->data_offset = avio_tell(ic->pb);
 
     return 0;
 }
@@ -392,8 +392,8 @@ int avformat_queue_attached_pictures(AVFormatContext *s)
             if (!copy.buf)
                 return AVERROR(ENOMEM);
 
-            add_to_pktbuf(&s->raw_packet_buffer, &copy,
-                          &s->raw_packet_buffer_end);
+            add_to_pktbuf(&s->internal->raw_packet_buffer, &copy,
+                          &s->internal->raw_packet_buffer_end);
         }
     return 0;
 }
@@ -479,10 +479,10 @@ int avformat_open_input(AVFormatContext **ps, const char *filename,
     if ((ret = avformat_queue_attached_pictures(s)) < 0)
         goto fail;
 
-    if (!(s->flags&AVFMT_FLAG_PRIV_OPT) && s->pb && !s->data_offset)
-        s->data_offset = avio_tell(s->pb);
+    if (!(s->flags&AVFMT_FLAG_PRIV_OPT) && s->pb && !s->internal->data_offset)
+        s->internal->data_offset = avio_tell(s->pb);
 
-    s->raw_packet_buffer_remaining_size = RAW_PACKET_BUFFER_SIZE;
+    s->internal->raw_packet_buffer_remaining_size = RAW_PACKET_BUFFER_SIZE;
 
     if (options) {
         av_dict_free(options);
@@ -550,7 +550,7 @@ no_packet:
             }
         }
 
-        end=    s->raw_packet_buffer_remaining_size <= 0
+        end=    s->internal->raw_packet_buffer_remaining_size <= 0
                 || st->probe_packets<= 0;
 
         if (end || av_log2(pd->buf_size) != av_log2(pd->buf_size - pkt->size)) {
@@ -643,17 +643,17 @@ int ff_read_packet(AVFormatContext *s, AVPacket *pkt)
     AVStream *st;
 
     for (;;) {
-        AVPacketList *pktl = s->raw_packet_buffer;
+        AVPacketList *pktl = s->internal->raw_packet_buffer;
 
         if (pktl) {
             *pkt = pktl->pkt;
             st   = s->streams[pkt->stream_index];
-            if (s->raw_packet_buffer_remaining_size <= 0)
+            if (s->internal->raw_packet_buffer_remaining_size <= 0)
                 if ((err = probe_codec(s, st, NULL)) < 0)
                     return err;
             if (st->request_probe <= 0) {
-                s->raw_packet_buffer                 = pktl->next;
-                s->raw_packet_buffer_remaining_size += pkt->size;
+                s->internal->raw_packet_buffer                 = pktl->next;
+                s->internal->raw_packet_buffer_remaining_size += pkt->size;
                 av_free(pktl);
                 return 0;
             }
@@ -714,8 +714,9 @@ int ff_read_packet(AVFormatContext *s, AVPacket *pkt)
         if (!pktl && st->request_probe <= 0)
             return ret;
 
-        add_to_pktbuf(&s->raw_packet_buffer, pkt, &s->raw_packet_buffer_end);
-        s->raw_packet_buffer_remaining_size -= pkt->size;
+        add_to_pktbuf(&s->internal->raw_packet_buffer, pkt,
+                      &s->internal->raw_packet_buffer_end);
+        s->internal->raw_packet_buffer_remaining_size -= pkt->size;
 
         if ((err = probe_codec(s, st, pkt)) < 0)
             return err;
@@ -827,8 +828,8 @@ static AVPacketList *get_next_pkt(AVFormatContext *s, AVStream *st, AVPacketList
 {
     if (pktl->next)
         return pktl->next;
-    if (pktl == s->packet_buffer_end)
-        return s->parse_queue;
+    if (pktl == s->internal->packet_buffer_end)
+        return s->internal->parse_queue;
     return NULL;
 }
 
@@ -878,7 +879,7 @@ static void update_initial_timestamps(AVFormatContext *s, int stream_index,
                                       int64_t dts, int64_t pts, AVPacket *pkt)
 {
     AVStream *st       = s->streams[stream_index];
-    AVPacketList *pktl = s->packet_buffer ? s->packet_buffer : s->parse_queue;
+    AVPacketList *pktl = s->internal->packet_buffer ? s->internal->packet_buffer : s->internal->parse_queue;
     int64_t pts_buffer[MAX_REORDER_DELAY+1];
     int64_t shift;
     int i, delay;
@@ -928,7 +929,7 @@ static void update_initial_timestamps(AVFormatContext *s, int stream_index,
 static void update_initial_durations(AVFormatContext *s, AVStream *st,
                                      int stream_index, int duration)
 {
-    AVPacketList *pktl = s->packet_buffer ? s->packet_buffer : s->parse_queue;
+    AVPacketList *pktl = s->internal->packet_buffer ? s->internal->packet_buffer : s->internal->parse_queue;
     int64_t cur_dts    = RELATIVE_TS_BASE;
 
     if (st->first_dts != AV_NOPTS_VALUE) {
@@ -954,7 +955,7 @@ static void update_initial_durations(AVFormatContext *s, AVStream *st,
             av_log(s, AV_LOG_DEBUG, "first_dts %s but no packet with dts in the queue\n", av_ts2str(st->first_dts));
             return;
         }
-        pktl          = s->packet_buffer ? s->packet_buffer : s->parse_queue;
+        pktl          = s->internal->packet_buffer ? s->internal->packet_buffer : s->internal->parse_queue;
         st->first_dts = cur_dts;
     } else if (st->cur_dts != RELATIVE_TS_BASE)
         return;
@@ -1064,7 +1065,7 @@ static void compute_pkt_fields(AVFormatContext *s, AVStream *st,
         }
     }
 
-    if (pkt->duration != 0 && (s->packet_buffer || s->parse_queue))
+    if (pkt->duration != 0 && (s->internal->packet_buffer || s->internal->parse_queue))
         update_initial_durations(s, st, pkt->stream_index, pkt->duration);
 
     /* Correct timestamps with byte offset if demuxers only have timestamps
@@ -1264,7 +1265,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
         if ((ret = av_dup_packet(&out_pkt)) < 0)
             goto fail;
 
-        if (!add_to_pktbuf(&s->parse_queue, &out_pkt, &s->parse_queue_end)) {
+        if (!add_to_pktbuf(&s->internal->parse_queue, &out_pkt, &s->internal->parse_queue_end)) {
             av_free_packet(&out_pkt);
             ret = AVERROR(ENOMEM);
             goto fail;
@@ -1309,7 +1310,7 @@ static int read_frame_internal(AVFormatContext *s, AVPacket *pkt)
 
     av_init_packet(pkt);
 
-    while (!got_packet && !s->parse_queue) {
+    while (!got_packet && !s->internal->parse_queue) {
         AVStream *st;
         AVPacket cur_pkt;
 
@@ -1394,8 +1395,8 @@ static int read_frame_internal(AVFormatContext *s, AVPacket *pkt)
         }
     }
 
-    if (!got_packet && s->parse_queue)
-        ret = read_from_packet_buffer(&s->parse_queue, &s->parse_queue_end, pkt);
+    if (!got_packet && s->internal->parse_queue)
+        ret = read_from_packet_buffer(&s->internal->parse_queue, &s->internal->parse_queue_end, pkt);
 
     if (ret >= 0) {
         AVStream *st = s->streams[pkt->stream_index];
@@ -1470,9 +1471,9 @@ int av_read_frame(AVFormatContext *s, AVPacket *pkt)
     AVStream *st;
 
     if (!genpts) {
-        ret = s->packet_buffer
-              ? read_from_packet_buffer(&s->packet_buffer,
-                                        &s->packet_buffer_end, pkt)
+        ret = s->internal->packet_buffer
+              ? read_from_packet_buffer(&s->internal->packet_buffer,
+                                        &s->internal->packet_buffer_end, pkt)
               : read_frame_internal(s, pkt);
         if (ret < 0)
             return ret;
@@ -1480,7 +1481,7 @@ int av_read_frame(AVFormatContext *s, AVPacket *pkt)
     }
 
     for (;;) {
-        AVPacketList *pktl = s->packet_buffer;
+        AVPacketList *pktl = s->internal->packet_buffer;
 
         if (pktl) {
             AVPacket *next_pkt = &pktl->pkt;
@@ -1512,15 +1513,15 @@ int av_read_frame(AVFormatContext *s, AVPacket *pkt)
                     // 3. the packets for this stream at the end of the files had valid dts.
                     next_pkt->pts = last_dts + next_pkt->duration;
                 }
-                pktl = s->packet_buffer;
+                pktl = s->internal->packet_buffer;
             }
 
             /* read packet from packet buffer, if there is data */
             st = s->streams[next_pkt->stream_index];
             if (!(next_pkt->pts == AV_NOPTS_VALUE && st->discard < AVDISCARD_ALL &&
                   next_pkt->dts != AV_NOPTS_VALUE && !eof)) {
-                ret = read_from_packet_buffer(&s->packet_buffer,
-                                               &s->packet_buffer_end, pkt);
+                ret = read_from_packet_buffer(&s->internal->packet_buffer,
+                                               &s->internal->packet_buffer_end, pkt);
                 goto return_packet;
             }
         }
@@ -1534,8 +1535,8 @@ int av_read_frame(AVFormatContext *s, AVPacket *pkt)
                 return ret;
         }
 
-        if (av_dup_packet(add_to_pktbuf(&s->packet_buffer, pkt,
-                                        &s->packet_buffer_end)) < 0)
+        if (av_dup_packet(add_to_pktbuf(&s->internal->packet_buffer, pkt,
+                                        &s->internal->packet_buffer_end)) < 0)
             return AVERROR(ENOMEM);
     }
 
@@ -1558,11 +1559,13 @@ return_packet:
 /* XXX: suppress the packet queue */
 static void flush_packet_queue(AVFormatContext *s)
 {
-    free_packet_buffer(&s->parse_queue,       &s->parse_queue_end);
-    free_packet_buffer(&s->packet_buffer,     &s->packet_buffer_end);
-    free_packet_buffer(&s->raw_packet_buffer, &s->raw_packet_buffer_end);
+    if (!s->internal)
+        return;
+    free_packet_buffer(&s->internal->parse_queue,       &s->internal->parse_queue_end);
+    free_packet_buffer(&s->internal->packet_buffer,     &s->internal->packet_buffer_end);
+    free_packet_buffer(&s->internal->raw_packet_buffer, &s->internal->raw_packet_buffer_end);
 
-    s->raw_packet_buffer_remaining_size = RAW_PACKET_BUFFER_SIZE;
+    s->internal->raw_packet_buffer_remaining_size = RAW_PACKET_BUFFER_SIZE;
 }
 
 /*******************************************************/
@@ -1900,7 +1903,7 @@ int64_t ff_gen_search(AVFormatContext *s, int stream_index, int64_t target_ts,
     av_dlog(s, "gen_seek: %d %s\n", stream_index, av_ts2str(target_ts));
 
     if (ts_min == AV_NOPTS_VALUE) {
-        pos_min = s->data_offset;
+        pos_min = s->internal->data_offset;
         ts_min  = ff_read_timestamp(s, stream_index, &pos_min, INT64_MAX, read_timestamp);
         if (ts_min == AV_NOPTS_VALUE)
             return -1;
@@ -1996,7 +1999,7 @@ static int seek_frame_byte(AVFormatContext *s, int stream_index,
 {
     int64_t pos_min, pos_max;
 
-    pos_min = s->data_offset;
+    pos_min = s->internal->data_offset;
     pos_max = avio_size(s->pb) - 1;
 
     if (pos < pos_min)
@@ -2038,7 +2041,7 @@ static int seek_frame_generic(AVFormatContext *s, int stream_index,
                 return ret;
             ff_update_cur_dts(s, st, ie->timestamp);
         } else {
-            if ((ret = avio_seek(s->pb, s->data_offset, SEEK_SET)) < 0)
+            if ((ret = avio_seek(s->pb, s->internal->data_offset, SEEK_SET)) < 0)
                 return ret;
         }
         for (;;) {
@@ -2347,8 +2350,8 @@ static void estimate_timings_from_bit_rate(AVFormatContext *ic)
     if (ic->duration == AV_NOPTS_VALUE &&
         ic->bit_rate != 0) {
         filesize = ic->pb ? avio_size(ic->pb) : 0;
-        if (filesize > ic->data_offset) {
-            filesize -= ic->data_offset;
+        if (filesize > ic->internal->data_offset) {
+            filesize -= ic->internal->data_offset;
             for (i = 0; i < ic->nb_streams; i++) {
                 st      = ic->streams[i];
                 if (   st->time_base.num <= INT64_MAX / ic->bit_rate
@@ -3178,10 +3181,11 @@ int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
         }
 
         if (ic->flags & AVFMT_FLAG_NOBUFFER)
-            free_packet_buffer(&ic->packet_buffer, &ic->packet_buffer_end);
+            free_packet_buffer(&ic->internal->packet_buffer,
+                               &ic->internal->packet_buffer_end);
         {
-            pkt = add_to_pktbuf(&ic->packet_buffer, &pkt1,
-                                &ic->packet_buffer_end);
+            pkt = add_to_pktbuf(&ic->internal->packet_buffer, &pkt1,
+                                &ic->internal->packet_buffer_end);
             if (!pkt) {
                 ret = AVERROR(ENOMEM);
                 goto find_stream_info_err;
diff --git a/libavformat/version.h b/libavformat/version.h
index 9a38df9a0a..edad275598 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -31,7 +31,7 @@
 
 #define LIBAVFORMAT_VERSION_MAJOR 56
 #define LIBAVFORMAT_VERSION_MINOR  19
-#define LIBAVFORMAT_VERSION_MICRO 100
+#define LIBAVFORMAT_VERSION_MICRO 101
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
                                                LIBAVFORMAT_VERSION_MINOR, \
diff --git a/libavformat/vqf.c b/libavformat/vqf.c
index 15e8246432..ce07ca7851 100644
--- a/libavformat/vqf.c
+++ b/libavformat/vqf.c
@@ -275,7 +275,7 @@ static int vqf_read_seek(AVFormatContext *s,
     st->cur_dts = av_rescale(pos, st->time_base.den,
                              st->codec->bit_rate * (int64_t)st->time_base.num);
 
-    if ((ret = avio_seek(s->pb, ((pos-7) >> 3) + s->data_offset, SEEK_SET)) < 0)
+    if ((ret = avio_seek(s->pb, ((pos-7) >> 3) + s->internal->data_offset, SEEK_SET)) < 0)
         return ret;
 
     c->remaining_bits = -7 - ((pos-7)&7);
diff --git a/libavformat/yop.c b/libavformat/yop.c
index 07086d53b8..81b3cc2b32 100644
--- a/libavformat/yop.c
+++ b/libavformat/yop.c
@@ -199,7 +199,7 @@ static int yop_read_seek(AVFormatContext *s, int stream_index,
     if (!stream_index)
         return -1;
 
-    pos_min        = s->data_offset;
+    pos_min        = s->internal->data_offset;
     pos_max        = avio_size(s->pb) - yop->frame_size;
     frame_count    = (pos_max - pos_min) / yop->frame_size;