ffmpeg-2.8.5

git-svn-id: svn://kolibrios.org@6147 a494cfbc-eb01-0410-851d-a64ba20cac60

contrib/sdk/sources/ffmpeg/ffmpeg-2.8/libavcodec/opus_parser.c

@@ -0,0 +1,188 @@
+/*
+ * Copyright (c) 2013-2014 Mozilla Corporation
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * Opus parser
+ *
+ * Determines the duration for each packet.
+ */
+
+#include "avcodec.h"
+#include "bytestream.h"
+#include "opus.h"
+#include "parser.h"
+
+typedef struct OpusParseContext {
+    OpusContext ctx;
+    OpusPacket pkt;
+    int extradata_parsed;
+    ParseContext pc;
+    int ts_framing;
+} OpusParseContext;
+
+static const uint8_t *parse_opus_ts_header(const uint8_t *start, int *payload_len, int buf_len)
+{
+    const uint8_t *buf = start + 1;
+    int start_trim_flag, end_trim_flag, control_extension_flag, control_extension_length;
+    uint8_t flags;
+
+    GetByteContext gb;
+    bytestream2_init(&gb, buf, buf_len);
+
+    flags = bytestream2_get_byte(&gb);
+    start_trim_flag        = (flags >> 4) & 1;
+    end_trim_flag          = (flags >> 3) & 1;
+    control_extension_flag = (flags >> 2) & 1;
+
+    *payload_len = 0;
+    while (bytestream2_peek_byte(&gb) == 0xff)
+        *payload_len += bytestream2_get_byte(&gb);
+
+    *payload_len += bytestream2_get_byte(&gb);
+
+    if (start_trim_flag)
+        bytestream2_skip(&gb, 2);
+    if (end_trim_flag)
+        bytestream2_skip(&gb, 2);
+    if (control_extension_flag) {
+        control_extension_length = bytestream2_get_byte(&gb);
+        bytestream2_skip(&gb, control_extension_length);
+    }
+
+    return buf + bytestream2_tell(&gb);
+}
+
+/**
+ * Find the end of the current frame in the bitstream.
+ * @return the position of the first byte of the next frame, or -1
+ */
+static int opus_find_frame_end(AVCodecParserContext *ctx, AVCodecContext *avctx,
+                               const uint8_t *buf, int buf_size, int *header_len)
+{
+    OpusParseContext *s = ctx->priv_data;
+    ParseContext *pc    = &s->pc;
+    int ret, start_found, i = 0, payload_len = 0;
+    const uint8_t *payload;
+    uint32_t state;
+    uint16_t hdr;
+    *header_len = 0;
+
+    if (!buf_size)
+        return 0;
+
+    start_found = pc->frame_start_found;
+    state = pc->state;
+    payload = buf;
+
+    /* Check if we're using Opus in MPEG-TS framing */
+    if (!s->ts_framing && buf_size > 2) {
+        hdr = AV_RB16(buf);
+        if ((hdr & OPUS_TS_MASK) == OPUS_TS_HEADER)
+            s->ts_framing = 1;
+    }
+
+    if (s->ts_framing && !start_found) {
+        for (i = 0; i < buf_size-2; i++) {
+            state = (state << 8) | payload[i];
+            if ((state & OPUS_TS_MASK) == OPUS_TS_HEADER) {
+                payload = parse_opus_ts_header(payload, &payload_len, buf_size - i);
+                *header_len = payload - buf;
+                start_found = 1;
+                break;
+            }
+        }
+    }
+
+    if (!s->ts_framing)
+        payload_len = buf_size;
+
+    if (avctx->extradata && !s->extradata_parsed) {
+        ret = ff_opus_parse_extradata(avctx, &s->ctx);
+        if (ret < 0) {
+            av_log(avctx, AV_LOG_ERROR, "Error parsing Ogg extradata.\n");
+            return AVERROR_INVALIDDATA;
+        }
+        av_freep(&s->ctx.channel_maps);
+        s->extradata_parsed = 1;
+    }
+
+    if (payload_len <= buf_size && (!s->ts_framing || start_found)) {
+        ret = ff_opus_parse_packet(&s->pkt, payload, payload_len, s->ctx.nb_streams > 1);
+        if (ret < 0) {
+            av_log(avctx, AV_LOG_ERROR, "Error parsing Opus packet header.\n");
+            pc->frame_start_found = 0;
+            return AVERROR_INVALIDDATA;
+        }
+
+        ctx->duration = s->pkt.frame_count * s->pkt.frame_duration;
+    }
+
+    if (s->ts_framing) {
+        if (start_found) {
+            if (payload_len + *header_len <= buf_size) {
+                pc->frame_start_found = 0;
+                pc->state             = -1;
+                return payload_len + *header_len;
+            }
+        }
+
+        pc->frame_start_found = start_found;
+        pc->state = state;
+        return END_NOT_FOUND;
+    }
+
+    return buf_size;
+}
+
+static int opus_parse(AVCodecParserContext *ctx, AVCodecContext *avctx,
+                       const uint8_t **poutbuf, int *poutbuf_size,
+                       const uint8_t *buf, int buf_size)
+{
+    OpusParseContext *s = ctx->priv_data;
+    ParseContext *pc    = &s->pc;
+    int next, header_len;
+
+    next = opus_find_frame_end(ctx, avctx, buf, buf_size, &header_len);
+
+    if (s->ts_framing && next != AVERROR_INVALIDDATA &&
+        ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
+        *poutbuf      = NULL;
+        *poutbuf_size = 0;
+        return buf_size;
+    }
+
+    if (next == AVERROR_INVALIDDATA){
+        *poutbuf      = NULL;
+        *poutbuf_size = 0;
+        return buf_size;
+    }
+
+    *poutbuf      = buf + header_len;
+    *poutbuf_size = buf_size - header_len;
+    return next;
+}
+
+AVCodecParser ff_opus_parser = {
+    .codec_ids      = { AV_CODEC_ID_OPUS },
+    .priv_data_size = sizeof(OpusParseContext),
+    .parser_parse   = opus_parse,
+    .parser_close   = ff_parse_close
+};