rtpdec: Add a dynamic payload handler for the x-Purevoice format, RFC 2658

This fixes roundup issue 2390.

Originally committed as revision 25889 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 228 insertions, 0 deletions

diff --git a/libavformat/rtpdec_qcelp.c b/libavformat/rtpdec_qcelp.c
new file mode 100644
index 0000000000..792e7dcad4
--- /dev/null
+++ b/libavformat/rtpdec_qcelp.c
@@ -0,0 +1,228 @@
+/**
+ * RTP Depacketization of QCELP/PureVoice, RFC 2658
+ * Copyright (c) 2010 Martin Storsjo
+ *
+ * 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 "rtpdec_formats.h"
+
+static const uint8_t frame_sizes[] = {
+    1, 4, 8, 17, 35
+};
+
+typedef struct {
+    int pos;
+    int size;
+    /* The largest frame is 35 bytes, only 10 frames are allowed per
+     * packet, and we return the first one immediately, so allocate
+     * space for 9 frames */
+    uint8_t data[35*9];
+} InterleavePacket;
+
+struct PayloadContext {
+    int interleave_size;
+    int interleave_index;
+    InterleavePacket group[6];
+    int group_finished;
+
+    /* The maximum packet size, 10 frames of 35 bytes each, and one
+     * packet header byte. */
+    uint8_t  next_data[1 + 35*10];
+    int      next_size;
+    uint32_t next_timestamp;
+};
+
+static PayloadContext *qcelp_new_context(void)
+{
+    return av_mallocz(sizeof(PayloadContext));
+}
+
+static void qcelp_free_context(PayloadContext *data)
+{
+    av_free(data);
+}
+
+static int return_stored_frame(AVFormatContext *ctx, PayloadContext *data,
+                               AVStream *st, AVPacket *pkt, uint32_t *timestamp,
+                               const uint8_t *buf, int len);
+
+static int store_packet(AVFormatContext *ctx, PayloadContext *data,
+                        AVStream *st, AVPacket *pkt, uint32_t *timestamp,
+                        const uint8_t *buf, int len)
+{
+    int interleave_size, interleave_index;
+    int frame_size, ret;
+    InterleavePacket* ip;
+
+    if (len < 2)
+        return AVERROR_INVALIDDATA;
+
+    interleave_size  = buf[0] >> 3 & 7;
+    interleave_index = buf[0]      & 7;
+
+    if (interleave_size > 5) {
+        av_log(ctx, AV_LOG_ERROR, "Invalid interleave size %d\n",
+                                   interleave_size);
+        return AVERROR_INVALIDDATA;
+    }
+    if (interleave_index > interleave_size) {
+        av_log(ctx, AV_LOG_ERROR, "Invalid interleave index %d/%d\n",
+                                   interleave_index, interleave_size);
+        return AVERROR_INVALIDDATA;
+    }
+    if (interleave_size != data->interleave_size) {
+        int i;
+        /* First packet, or changed interleave size */
+        data->interleave_size = interleave_size;
+        data->interleave_index = 0;
+        for (i = 0; i < 6; i++)
+            data->group[i].size = 0;
+    }
+
+    if (interleave_index < data->interleave_index) {
+        /* Wrapped around - missed the last packet of the previous group. */
+        if (data->group_finished) {
+            /* No more data in the packets in this interleaving group, just
+             * start processing the next one */
+            data->interleave_index = 0;
+        } else {
+            /* Stash away the current packet, emit everything we have of the
+             * previous group. */
+            for (; data->interleave_index <= interleave_size;
+                 data->interleave_index++)
+                data->group[data->interleave_index].size = 0;
+
+            if (len > sizeof(data->next_data))
+                return AVERROR_INVALIDDATA;
+            memcpy(data->next_data, buf, len);
+            data->next_size = len;
+            data->next_timestamp = *timestamp;
+            *timestamp = RTP_NOTS_VALUE;
+
+            data->interleave_index = 0;
+            return return_stored_frame(ctx, data, st, pkt, timestamp, buf, len);
+        }
+    }
+    if (interleave_index > data->interleave_index) {
+        /* We missed a packet */
+        for (; data->interleave_index < interleave_index;
+             data->interleave_index++)
+            data->group[data->interleave_index].size = 0;
+    }
+    data->interleave_index = interleave_index;
+
+    if (buf[1] >= FF_ARRAY_ELEMS(frame_sizes))
+        return AVERROR_INVALIDDATA;
+    frame_size = frame_sizes[buf[1]];
+    if (1 + frame_size > len)
+        return AVERROR_INVALIDDATA;
+
+    if (len - 1 - frame_size > sizeof(data->group[0].data))
+        return AVERROR_INVALIDDATA;
+
+    if ((ret = av_new_packet(pkt, frame_size)) < 0)
+        return ret;
+    memcpy(pkt->data, &buf[1], frame_size);
+    pkt->stream_index = st->index;
+
+    ip = &data->group[data->interleave_index];
+    ip->size = len - 1 - frame_size;
+    ip->pos = 0;
+    memcpy(ip->data, &buf[1 + frame_size], ip->size);
+    /* Each packet must contain the same number of frames according to the
+     * RFC. If there's no data left in this packet, there shouldn't be any
+     * in any of the other frames in the interleaving group either. */
+    data->group_finished = ip->size == 0;
+
+    if (interleave_index == interleave_size) {
+        data->interleave_index = 0;
+        return !data->group_finished;
+    } else {
+        data->interleave_index++;
+        return 0;
+    }
+}
+
+static int return_stored_frame(AVFormatContext *ctx, PayloadContext *data,
+                               AVStream *st, AVPacket *pkt, uint32_t *timestamp,
+                               const uint8_t *buf, int len)
+{
+    InterleavePacket* ip = &data->group[data->interleave_index];
+    int frame_size, ret;
+
+    if (data->group_finished && data->interleave_index == 0) {
+        *timestamp = data->next_timestamp;
+        ret = store_packet(ctx, data, st, pkt, timestamp, data->next_data,
+                           data->next_size);
+        data->next_size = 0;
+        return ret;
+    }
+
+    if (ip->size == 0) {
+        /* No stored data for this interleave block, output an empty packet */
+        if ((ret = av_new_packet(pkt, 1)) < 0)
+            return ret;
+        pkt->data[0] = 0; // Blank - could also be 14, Erasure
+    } else {
+        if (ip->pos >= ip->size)
+            return AVERROR_INVALIDDATA;
+        if (ip->data[ip->pos] >= FF_ARRAY_ELEMS(frame_sizes))
+            return AVERROR_INVALIDDATA;
+        frame_size = frame_sizes[ip->data[ip->pos]];
+        if (ip->pos + frame_size > ip->size)
+            return AVERROR_INVALIDDATA;
+
+        if ((ret = av_new_packet(pkt, frame_size)) < 0)
+            return ret;
+        memcpy(pkt->data, &ip->data[ip->pos], frame_size);
+
+        ip->pos += frame_size;
+        data->group_finished = ip->pos >= ip->size;
+    }
+    pkt->stream_index = st->index;
+
+    if (data->interleave_index == data->interleave_size) {
+        data->interleave_index = 0;
+        if (!data->group_finished)
+            return 1;
+        else
+            return data->next_size > 0;
+    } else {
+        data->interleave_index++;
+        return 1;
+    }
+}
+
+static int qcelp_parse_packet(AVFormatContext *ctx, PayloadContext *data,
+                              AVStream *st, AVPacket *pkt, uint32_t *timestamp,
+                              const uint8_t *buf, int len, int flags)
+{
+    if (buf)
+        return store_packet(ctx, data, st, pkt, timestamp, buf, len);
+    else
+        return return_stored_frame(ctx, data, st, pkt, timestamp, buf, len);
+}
+
+RTPDynamicProtocolHandler ff_qcelp_dynamic_handler = {
+    .enc_name           = "x-Purevoice",
+    .codec_type         = AVMEDIA_TYPE_AUDIO,
+    .codec_id           = CODEC_ID_QCELP,
+    .open               = qcelp_new_context,
+    .close              = qcelp_free_context,
+    .parse_packet       = qcelp_parse_packet
+};