@@ -51,6 +51,20 @@ typedef struct MOVIentry {

     uint32_t     flags;

 } MOVIentry;

+typedef struct HintSample {

+    uint8_t *data;

+    int size;

+    int sample_number;

+    int offset;

+    int own_data;

+} HintSample;

+

+typedef struct {

+    int size;

+    int len;

+    HintSample *samples;

+} HintSampleQueue;

+

 typedef struct MOVIndex {

     int         mode;

     int         entry;

@@ -82,6 +96,8 @@ typedef struct MOVIndex {

     uint32_t    prev_rtp_ts;

     int64_t     cur_rtp_ts_unwrapped;

     uint32_t    max_packet_size;

+

+    HintSampleQueue sample_queue;

 } MOVTrack;

 typedef struct MOVMuxContext {

@@ -98,6 +98,188 @@ fail:

     return ret;

 }

+/**

+ * Remove the first sample from the sample queue.

+ */

+static void sample_queue_pop(HintSampleQueue *queue)

+{

+    if (queue->len <= 0)

+        return;

+    if (queue->samples[0].own_data)

+        av_free(queue->samples[0].data);

+    queue->len--;

+    memmove(queue->samples, queue->samples + 1, sizeof(HintSample)*queue->len);

+}

+

+/**

+ * Empty the sample queue, releasing all memory.

+ */

+static void sample_queue_free(HintSampleQueue *queue)

+{

+    int i;

+    for (i = 0; i < queue->len; i++)

+        if (queue->samples[i].own_data)

+            av_free(queue->samples[i].data);

+    av_freep(&queue->samples);

+    queue->len = 0;

+    queue->size = 0;

+}

+

+/**

+ * Add a reference to the sample data to the sample queue. The data is

+ * not copied. sample_queue_retain should be called before pkt->data

+ * is reused/freed.

+ */

+static void sample_queue_push(HintSampleQueue *queue, AVPacket *pkt, int sample)

+{

+    /* No need to keep track of smaller samples, since describing them

+     * with immediates is more efficient. */

+    if (pkt->size <= 14)

+        return;

+    if (!queue->samples || queue->len >= queue->size) {

+        HintSample* samples;

+        queue->size += 10;

+        samples = av_realloc(queue->samples, sizeof(HintSample)*queue->size);

+        if (!samples)

+            return;

+        queue->samples = samples;

+    }

+    queue->samples[queue->len].data = pkt->data;

+    queue->samples[queue->len].size = pkt->size;

+    queue->samples[queue->len].sample_number = sample;

+    queue->samples[queue->len].offset = 0;

+    queue->samples[queue->len].own_data = 0;

+    queue->len++;

+}

+

+/**

+ * Make local copies of all referenced sample data in the queue.

+ */

+static void sample_queue_retain(HintSampleQueue *queue)

+{

+    int i;

+    for (i = 0; i < queue->len; ) {

+        HintSample *sample = &queue->samples[i];

+        if (!sample->own_data) {

+            uint8_t* ptr = av_malloc(sample->size);

+            if (!ptr) {

+                /* Unable to allocate memory for this one, remove it */

+                memmove(queue->samples + i, queue->samples + i + 1,

+                        sizeof(HintSample)*(queue->len - i - 1));

+                queue->len--;

+                continue;

+            }

+            memcpy(ptr, sample->data, sample->size);

+            sample->data = ptr;

+            sample->own_data = 1;

+        }

+        i++;

+    }

+}

+

+/**

+ * Find matches of needle[n_pos ->] within haystack. If a sufficiently

+ * large match is found, matching bytes before n_pos are included

+ * in the match, too (within the limits of the arrays).

+ *

+ * @param haystack buffer that may contain parts of needle

+ * @param h_len length of the haystack buffer

+ * @param needle buffer containing source data that have been used to

+ *               construct haystack

+ * @param n_pos start position in needle used for looking for matches

+ * @param n_len length of the needle buffer

+ * @param match_h_offset_ptr offset of the first matching byte within haystack

+ * @param match_n_offset_ptr offset of the first matching byte within needle

+ * @param match_len_ptr length of the matched segment

+ * @return 0 if a match was found, < 0 if no match was found

+ */

+static int match_segments(const uint8_t *haystack, int h_len,

+                          const uint8_t *needle, int n_pos, int n_len,

+                          int *match_h_offset_ptr, int *match_n_offset_ptr,

+                          int *match_len_ptr)

+{

+    int h_pos;

+    for (h_pos = 0; h_pos < h_len; h_pos++) {

+        int match_len = 0;

+        int match_h_pos, match_n_pos;

+

+        /* Check how many bytes match at needle[n_pos] and haystack[h_pos] */

+        while (h_pos + match_len < h_len && n_pos + match_len < n_len &&

+               needle[n_pos + match_len] == haystack[h_pos + match_len])

+            match_len++;

+        if (match_len <= 8)

+            continue;

+

+        /* If a sufficiently large match was found, try to expand

+         * the matched segment backwards. */

+        match_h_pos = h_pos;

+        match_n_pos = n_pos;

+        while (match_n_pos > 0 && match_h_pos > 0 &&

+               needle[match_n_pos - 1] == haystack[match_h_pos - 1]) {

+            match_n_pos--;

+            match_h_pos--;

+            match_len++;

+        }

+        if (match_len <= 14)

+            continue;

+        *match_h_offset_ptr = match_h_pos;

+        *match_n_offset_ptr = match_n_pos;

+        *match_len_ptr = match_len;

+        return 0;

+    }

+    return -1;

+}

+

+/**

+ * Look for segments in samples in the sample queue matching the data

+ * in ptr. Samples not matching are removed from the queue. If a match

+ * is found, the next time it will look for matches starting from the

+ * end of the previous matched segment.

+ *

+ * @param data data to find matches for in the sample queue

+ * @param len length of the data buffer

+ * @param queue samples used for looking for matching segments

+ * @param pos the offset in data of the matched segment

+ * @param match_sample the number of the sample that contained the match

+ * @param match_offset the offset of the matched segment within the sample

+ * @param match_len the length of the matched segment

+ * @return 0 if a match was found, < 0 if no match was found

+ */

+static int find_sample_match(const uint8_t *data, int len,

+                             HintSampleQueue *queue, int *pos,

+                             int *match_sample, int *match_offset,

+                             int *match_len)

+{

+    while (queue->len > 0) {

+        HintSample *sample = &queue->samples[0];

+        /* If looking for matches in a new sample, skip the first 5 bytes,

+         * since they often may be modified/removed in the output packet. */

+        if (sample->offset == 0 && sample->size > 5)

+            sample->offset = 5;

+

+        if (match_segments(data, len, sample->data, sample->offset,

+                           sample->size, pos, match_offset, match_len) == 0) {

+            *match_sample = sample->sample_number;

+            /* Next time, look for matches at this offset, with a little

+             * margin to this match. */

+            sample->offset = *match_offset + *match_len + 5;

+            if (sample->offset + 10 >= sample->size)

+                sample_queue_pop(queue); /* Not enough useful data left */

+            return 0;

+        }

+

+        if (sample->offset < 10 && sample->size > 20) {

+            /* No match found from the start of the sample,

+             * try from the middle of the sample instead. */

+            sample->offset = sample->size/2;

+        } else {

+            /* No match for this sample, remove it */

+            sample_queue_pop(queue);

+        }

+    }

+    return -1;

+}

+

 static void output_immediate(const uint8_t *data, int size,

                              ByteIOContext *out, int *entries)

 {

@@ -118,10 +300,36 @@ static void output_immediate(const uint8_t *data, int size,

     }

 }

+static void output_match(ByteIOContext *out, int match_sample,

+                         int match_offset, int match_len, int *entries)

+{

+    put_byte(out, 2); /* sample constructor */

+    put_byte(out, 0); /* track reference */

+    put_be16(out, match_len);

+    put_be32(out, match_sample);

+    put_be32(out, match_offset);

+    put_be16(out, 1); /* bytes per block */

+    put_be16(out, 1); /* samples per block */

+    (*entries)++;

+}

+

 static void describe_payload(const uint8_t *data, int size,

-                             ByteIOContext *out, int *entries)

+                             ByteIOContext *out, int *entries,

+                             HintSampleQueue *queue)

 {

     /* Describe the payload using different constructors */

+    while (size > 0) {

+        int match_sample, match_offset, match_len, pos;

+        if (find_sample_match(data, size, queue, &pos, &match_sample,

+                              &match_offset, &match_len) < 0)

+            break;

+        output_immediate(data, pos, out, entries);

+        data += pos;

+        size -= pos;

+        output_match(out, match_sample, match_offset, match_len, entries);

+        data += match_len;

+        size -= match_len;

+    }

     output_immediate(data, size, out, entries);

 }

@@ -195,7 +403,7 @@ static int write_hint_packets(ByteIOContext *out, const uint8_t *data,

         entries = 0;

         /* Write one or more constructors describing the payload data */

-        describe_payload(data, packet_len, out, &entries);

+        describe_payload(data, packet_len, out, &entries, &trk->sample_queue);

         data += packet_len;

         size -= packet_len;

@@ -230,6 +438,8 @@ int ff_mov_add_hinted_packet(AVFormatContext *s, AVPacket *pkt,

     if (!rtp_ctx->pb)

         return AVERROR(ENOMEM);

+    sample_queue_push(&trk->sample_queue, pkt, sample);

+

     /* Feed the packet to the RTP muxer */

     local_pkt = *pkt;

     local_pkt.stream_index = 0;

@@ -269,6 +479,7 @@ int ff_mov_add_hinted_packet(AVFormatContext *s, AVPacket *pkt,

         ff_mov_write_packet(s, &hint_pkt);

 done:

     av_free(buf);

+    sample_queue_retain(&trk->sample_queue);

     return ret;

 }

@@ -277,6 +488,7 @@ void ff_mov_close_hinting(MOVTrack *track) {

     uint8_t *ptr;

     av_freep(&track->enc);

+    sample_queue_free(&track->sample_queue);

     if (!rtp_ctx)

         return;

     if (rtp_ctx->pb) {