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Diffstat (limited to 'media/ffvpx/libavcodec/vorbis_parser.c')
-rw-r--r--media/ffvpx/libavcodec/vorbis_parser.c343
1 files changed, 343 insertions, 0 deletions
diff --git a/media/ffvpx/libavcodec/vorbis_parser.c b/media/ffvpx/libavcodec/vorbis_parser.c
new file mode 100644
index 0000000000..a7d15d4ce9
--- /dev/null
+++ b/media/ffvpx/libavcodec/vorbis_parser.c
@@ -0,0 +1,343 @@
+/*
+ * Copyright (c) 2012 Justin Ruggles
+ *
+ * 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
+ * Vorbis audio parser
+ *
+ * Determines the duration for each packet.
+ */
+
+#include "config_components.h"
+
+#include "libavutil/log.h"
+
+#include "get_bits.h"
+#include "parser.h"
+#include "xiph.h"
+#include "vorbis_parser_internal.h"
+
+static const AVClass vorbis_parser_class = {
+ .class_name = "Vorbis parser",
+ .item_name = av_default_item_name,
+ .version = LIBAVUTIL_VERSION_INT,
+};
+
+static int parse_id_header(AVVorbisParseContext *s,
+ const uint8_t *buf, int buf_size)
+{
+ /* Id header should be 30 bytes */
+ if (buf_size < 30) {
+ av_log(s, AV_LOG_ERROR, "Id header is too short\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ /* make sure this is the Id header */
+ if (buf[0] != 1) {
+ av_log(s, AV_LOG_ERROR, "Wrong packet type in Id header\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ /* check for header signature */
+ if (memcmp(&buf[1], "vorbis", 6)) {
+ av_log(s, AV_LOG_ERROR, "Invalid packet signature in Id header\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ if (!(buf[29] & 0x1)) {
+ av_log(s, AV_LOG_ERROR, "Invalid framing bit in Id header\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ s->blocksize[0] = 1 << (buf[28] & 0xF);
+ s->blocksize[1] = 1 << (buf[28] >> 4);
+
+ return 0;
+}
+
+static int parse_setup_header(AVVorbisParseContext *s,
+ const uint8_t *buf, int buf_size)
+{
+ GetBitContext gb, gb0;
+ uint8_t *rev_buf;
+ int i, ret = 0;
+ int got_framing_bit, mode_count, got_mode_header, last_mode_count = 0;
+
+ /* avoid overread */
+ if (buf_size < 7) {
+ av_log(s, AV_LOG_ERROR, "Setup header is too short\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ /* make sure this is the Setup header */
+ if (buf[0] != 5) {
+ av_log(s, AV_LOG_ERROR, "Wrong packet type in Setup header\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ /* check for header signature */
+ if (memcmp(&buf[1], "vorbis", 6)) {
+ av_log(s, AV_LOG_ERROR, "Invalid packet signature in Setup header\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ /* reverse bytes so we can easily read backwards with get_bits() */
+ if (!(rev_buf = av_malloc(buf_size))) {
+ av_log(s, AV_LOG_ERROR, "Out of memory\n");
+ return AVERROR(ENOMEM);
+ }
+ for (i = 0; i < buf_size; i++)
+ rev_buf[i] = buf[buf_size - 1 - i];
+ init_get_bits(&gb, rev_buf, buf_size * 8);
+
+ got_framing_bit = 0;
+ while (get_bits_left(&gb) > 97) {
+ if (get_bits1(&gb)) {
+ got_framing_bit = get_bits_count(&gb);
+ break;
+ }
+ }
+ if (!got_framing_bit) {
+ av_log(s, AV_LOG_ERROR, "Invalid Setup header\n");
+ ret = AVERROR_INVALIDDATA;
+ goto bad_header;
+ }
+
+ /* Now we search backwards to find possible valid mode counts. This is not
+ * fool-proof because we could have false positive matches and read too
+ * far, but there isn't really any way to be sure without parsing through
+ * all the many variable-sized fields before the modes. This approach seems
+ * to work well in testing, and it is similar to how it is handled in
+ * liboggz. */
+ mode_count = 0;
+ got_mode_header = 0;
+ while (get_bits_left(&gb) >= 97) {
+ if (get_bits(&gb, 8) > 63 || get_bits(&gb, 16) || get_bits(&gb, 16))
+ break;
+ skip_bits(&gb, 1);
+ mode_count++;
+ if (mode_count > 64)
+ break;
+ gb0 = gb;
+ if (get_bits(&gb0, 6) + 1 == mode_count) {
+ got_mode_header = 1;
+ last_mode_count = mode_count;
+ }
+ }
+ if (!got_mode_header) {
+ av_log(s, AV_LOG_ERROR, "Invalid Setup header\n");
+ ret = AVERROR_INVALIDDATA;
+ goto bad_header;
+ }
+ /* All samples I've seen use <= 2 modes, so ask for a sample if we find
+ * more than that, as it is most likely a false positive. If we get any
+ * we may need to approach this the long way and parse the whole Setup
+ * header, but I hope very much that it never comes to that. */
+ if (last_mode_count > 2) {
+ avpriv_request_sample(s,
+ "%d modes (either a false positive or a "
+ "sample from an unknown encoder)",
+ last_mode_count);
+ }
+ /* We're limiting the mode count to 63 so that we know that the previous
+ * block flag will be in the first packet byte. */
+ if (last_mode_count > 63) {
+ av_log(s, AV_LOG_ERROR, "Unsupported mode count: %d\n",
+ last_mode_count);
+ ret = AVERROR_INVALIDDATA;
+ goto bad_header;
+ }
+ s->mode_count = mode_count = last_mode_count;
+ /* Determine the number of bits required to code the mode and turn that
+ * into a bitmask to directly access the mode from the first frame byte. */
+ s->mode_mask = ((1 << (av_log2(mode_count - 1) + 1)) - 1) << 1;
+ /* The previous window flag is the next bit after the mode */
+ s->prev_mask = (s->mode_mask | 0x1) + 1;
+
+ init_get_bits(&gb, rev_buf, buf_size * 8);
+ skip_bits_long(&gb, got_framing_bit);
+ for (i = mode_count - 1; i >= 0; i--) {
+ skip_bits_long(&gb, 40);
+ s->mode_blocksize[i] = get_bits1(&gb);
+ }
+
+bad_header:
+ av_free(rev_buf);
+ return ret;
+}
+
+static int vorbis_parse_init(AVVorbisParseContext *s,
+ const uint8_t *extradata, int extradata_size)
+{
+ const uint8_t *header_start[3];
+ int header_len[3];
+ int ret;
+
+ s->class = &vorbis_parser_class;
+ s->extradata_parsed = 1;
+
+ if ((ret = avpriv_split_xiph_headers(extradata,
+ extradata_size, 30,
+ header_start, header_len)) < 0) {
+ av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n");
+ return ret;
+ }
+
+ if ((ret = parse_id_header(s, header_start[0], header_len[0])) < 0)
+ return ret;
+
+ if ((ret = parse_setup_header(s, header_start[2], header_len[2])) < 0)
+ return ret;
+
+ s->valid_extradata = 1;
+ s->previous_blocksize = s->blocksize[s->mode_blocksize[0]];
+
+ return 0;
+}
+
+int av_vorbis_parse_frame_flags(AVVorbisParseContext *s, const uint8_t *buf,
+ int buf_size, int *flags)
+{
+ int duration = 0;
+
+ if (s->valid_extradata && buf_size > 0) {
+ int mode, current_blocksize;
+ int previous_blocksize = s->previous_blocksize;
+
+ if (buf[0] & 1) {
+ /* If the user doesn't care about special packets, it's a bad one. */
+ if (!flags)
+ goto bad_packet;
+
+ /* Set the flag for which kind of special packet it is. */
+ if (buf[0] == 1)
+ *flags |= VORBIS_FLAG_HEADER;
+ else if (buf[0] == 3)
+ *flags |= VORBIS_FLAG_COMMENT;
+ else if (buf[0] == 5)
+ *flags |= VORBIS_FLAG_SETUP;
+ else
+ goto bad_packet;
+
+ /* Special packets have no duration. */
+ return 0;
+
+bad_packet:
+ av_log(s, AV_LOG_ERROR, "Invalid packet\n");
+ return AVERROR_INVALIDDATA;
+ }
+ if (s->mode_count == 1)
+ mode = 0;
+ else
+ mode = (buf[0] & s->mode_mask) >> 1;
+ if (mode >= s->mode_count) {
+ av_log(s, AV_LOG_ERROR, "Invalid mode in packet\n");
+ return AVERROR_INVALIDDATA;
+ }
+ if(s->mode_blocksize[mode]){
+ int flag = !!(buf[0] & s->prev_mask);
+ previous_blocksize = s->blocksize[flag];
+ }
+ current_blocksize = s->blocksize[s->mode_blocksize[mode]];
+ duration = (previous_blocksize + current_blocksize) >> 2;
+ s->previous_blocksize = current_blocksize;
+ }
+
+ return duration;
+}
+
+int av_vorbis_parse_frame(AVVorbisParseContext *s, const uint8_t *buf,
+ int buf_size)
+{
+ return av_vorbis_parse_frame_flags(s, buf, buf_size, NULL);
+}
+
+void av_vorbis_parse_reset(AVVorbisParseContext *s)
+{
+ if (s->valid_extradata)
+ s->previous_blocksize = s->blocksize[0];
+}
+
+void av_vorbis_parse_free(AVVorbisParseContext **s)
+{
+ av_freep(s);
+}
+
+AVVorbisParseContext *av_vorbis_parse_init(const uint8_t *extradata,
+ int extradata_size)
+{
+ AVVorbisParseContext *s = av_mallocz(sizeof(*s));
+ int ret;
+
+ if (!s)
+ return NULL;
+
+ ret = vorbis_parse_init(s, extradata, extradata_size);
+ if (ret < 0) {
+ av_vorbis_parse_free(&s);
+ return NULL;
+ }
+
+ return s;
+}
+
+#if CONFIG_VORBIS_PARSER
+
+typedef struct VorbisParseContext {
+ AVVorbisParseContext *vp;
+} VorbisParseContext;
+
+static int vorbis_parse(AVCodecParserContext *s1, AVCodecContext *avctx,
+ const uint8_t **poutbuf, int *poutbuf_size,
+ const uint8_t *buf, int buf_size)
+{
+ VorbisParseContext *s = s1->priv_data;
+ int duration;
+
+ if (!s->vp && avctx->extradata && avctx->extradata_size) {
+ s->vp = av_vorbis_parse_init(avctx->extradata, avctx->extradata_size);
+ }
+ if (!s->vp)
+ goto end;
+
+ if ((duration = av_vorbis_parse_frame(s->vp, buf, buf_size)) >= 0)
+ s1->duration = duration;
+
+end:
+ /* always return the full packet. this parser isn't doing any splitting or
+ combining, only packet analysis */
+ *poutbuf = buf;
+ *poutbuf_size = buf_size;
+ return buf_size;
+}
+
+static void vorbis_parser_close(AVCodecParserContext *ctx)
+{
+ VorbisParseContext *s = ctx->priv_data;
+ av_vorbis_parse_free(&s->vp);
+}
+
+const AVCodecParser ff_vorbis_parser = {
+ .codec_ids = { AV_CODEC_ID_VORBIS },
+ .priv_data_size = sizeof(VorbisParseContext),
+ .parser_parse = vorbis_parse,
+ .parser_close = vorbis_parser_close,
+};
+#endif /* CONFIG_VORBIS_PARSER */
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