58 lines
1.4 KiB
C
58 lines
1.4 KiB
C
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#include "ogg_demux.h"
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static uint32_t le32(const uint8_t* p)
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{
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return (uint32_t)p[0]
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| ((uint32_t)p[1] << 8)
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| ((uint32_t)p[2] << 16)
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| ((uint32_t)p[3] << 24);
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}
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int ogg_parse_page(const uint8_t* buf, int buf_len, ogg_page_t* page)
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{
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if (buf_len < 27)
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return -1;
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/* 校验 "OggS" */
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if (buf[0] != 'O' || buf[1] != 'g' || buf[2] != 'g' || buf[3] != 'S')
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return -2;
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/* 拷贝页头 */
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for (int i = 0; i < 27; ++i)
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page->header[i] = buf[i];
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page->seg_count = buf[26];
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if (buf_len < 27 + page->seg_count)
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return -3;
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/* 读取 segment table */
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for (int i = 0; i < page->seg_count; ++i)
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page->seg_table[i] = buf[27 + i];
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/* 计算 body 大小 */
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uint32_t body_size = 0;
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for (int i = 0; i < page->seg_count; ++i)
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body_size += page->seg_table[i];
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page->body_size = body_size;
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if (buf_len < 27 + page->seg_count + body_size)
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return -4;
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return (int)body_size;
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}
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int ogg_extract_packet(const uint8_t* body, const ogg_page_t* page,
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uint8_t* packet, int packet_buf_size)
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{
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/* 极简版：假设一个页里只有一个完整 packet（常见于 OpusHead / OpusTags） */
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uint32_t total = page->body_size;
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if (total > (uint32_t)packet_buf_size)
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return -1;
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for (uint32_t i = 0; i < total; ++i)
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packet[i] = body[i];
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return (int)total;
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}
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