diff options
Diffstat (limited to 'drivers/media/v4l2-core/v4l2-jpeg.c')
| -rw-r--r-- | drivers/media/v4l2-core/v4l2-jpeg.c | 713 |
1 files changed, 713 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/v4l2-jpeg.c b/drivers/media/v4l2-core/v4l2-jpeg.c new file mode 100644 index 000000000000..36a0f1a1b0d9 --- /dev/null +++ b/drivers/media/v4l2-core/v4l2-jpeg.c @@ -0,0 +1,713 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * V4L2 JPEG header parser helpers. + * + * Copyright (C) 2019 Pengutronix, Philipp Zabel <kernel@pengutronix.de> + * + * For reference, see JPEG ITU-T.81 (ISO/IEC 10918-1) [1] + * + * [1] https://www.w3.org/Graphics/JPEG/itu-t81.pdf + */ + +#include <linux/unaligned.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/types.h> +#include <media/v4l2-jpeg.h> + +MODULE_DESCRIPTION("V4L2 JPEG header parser helpers"); +MODULE_AUTHOR("Philipp Zabel <kernel@pengutronix.de>"); +MODULE_LICENSE("GPL"); + +/* Table B.1 - Marker code assignments */ +#define SOF0 0xffc0 /* start of frame */ +#define SOF1 0xffc1 +#define SOF2 0xffc2 +#define SOF3 0xffc3 +#define SOF5 0xffc5 +#define SOF7 0xffc7 +#define JPG 0xffc8 /* extensions */ +#define SOF9 0xffc9 +#define SOF11 0xffcb +#define SOF13 0xffcd +#define SOF15 0xffcf +#define DHT 0xffc4 /* huffman table */ +#define DAC 0xffcc /* arithmetic coding conditioning */ +#define RST0 0xffd0 /* restart */ +#define RST7 0xffd7 +#define SOI 0xffd8 /* start of image */ +#define EOI 0xffd9 /* end of image */ +#define SOS 0xffda /* start of stream */ +#define DQT 0xffdb /* quantization table */ +#define DNL 0xffdc /* number of lines */ +#define DRI 0xffdd /* restart interval */ +#define DHP 0xffde /* hierarchical progression */ +#define EXP 0xffdf /* expand reference */ +#define APP0 0xffe0 /* application data */ +#define APP14 0xffee /* application data for colour encoding */ +#define APP15 0xffef +#define JPG0 0xfff0 /* extensions */ +#define JPG13 0xfffd +#define COM 0xfffe /* comment */ +#define TEM 0xff01 /* temporary */ + +/* Luma and chroma qp tables to achieve 50% compression quality + * This is as per example in Annex K.1 of ITU-T.81 + */ +const u8 v4l2_jpeg_ref_table_luma_qt[V4L2_JPEG_PIXELS_IN_BLOCK] = { + 16, 11, 10, 16, 24, 40, 51, 61, + 12, 12, 14, 19, 26, 58, 60, 55, + 14, 13, 16, 24, 40, 57, 69, 56, + 14, 17, 22, 29, 51, 87, 80, 62, + 18, 22, 37, 56, 68, 109, 103, 77, + 24, 35, 55, 64, 81, 104, 113, 92, + 49, 64, 78, 87, 103, 121, 120, 101, + 72, 92, 95, 98, 112, 100, 103, 99 +}; +EXPORT_SYMBOL_GPL(v4l2_jpeg_ref_table_luma_qt); + +const u8 v4l2_jpeg_ref_table_chroma_qt[V4L2_JPEG_PIXELS_IN_BLOCK] = { + 17, 18, 24, 47, 99, 99, 99, 99, + 18, 21, 26, 66, 99, 99, 99, 99, + 24, 26, 56, 99, 99, 99, 99, 99, + 47, 66, 99, 99, 99, 99, 99, 99, + 99, 99, 99, 99, 99, 99, 99, 99, + 99, 99, 99, 99, 99, 99, 99, 99, + 99, 99, 99, 99, 99, 99, 99, 99, + 99, 99, 99, 99, 99, 99, 99, 99 +}; +EXPORT_SYMBOL_GPL(v4l2_jpeg_ref_table_chroma_qt); + +/* Zigzag scan pattern indexes */ +const u8 v4l2_jpeg_zigzag_scan_index[V4L2_JPEG_PIXELS_IN_BLOCK] = { + 0, 1, 8, 16, 9, 2, 3, 10, + 17, 24, 32, 25, 18, 11, 4, 5, + 12, 19, 26, 33, 40, 48, 41, 34, + 27, 20, 13, 6, 7, 14, 21, 28, + 35, 42, 49, 56, 57, 50, 43, 36, + 29, 22, 15, 23, 30, 37, 44, 51, + 58, 59, 52, 45, 38, 31, 39, 46, + 53, 60, 61, 54, 47, 55, 62, 63 +}; +EXPORT_SYMBOL_GPL(v4l2_jpeg_zigzag_scan_index); + +/* + * Contains the data that needs to be sent in the marker segment of an + * interchange format JPEG stream or an abbreviated format table specification + * data stream. Specifies the huffman table used for encoding the luminance DC + * coefficient differences. The table represents Table K.3 of ITU-T.81 + */ +const u8 v4l2_jpeg_ref_table_luma_dc_ht[V4L2_JPEG_REF_HT_DC_LEN] = { + 0x00, 0x01, 0x05, 0x01, 0x01, 0x01, 0x01, 0x01, + 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B +}; +EXPORT_SYMBOL_GPL(v4l2_jpeg_ref_table_luma_dc_ht); + +/* + * Contains the data that needs to be sent in the marker segment of an + * interchange format JPEG stream or an abbreviated format table specification + * data stream. Specifies the huffman table used for encoding the luminance AC + * coefficients. The table represents Table K.5 of ITU-T.81 + */ +const u8 v4l2_jpeg_ref_table_luma_ac_ht[V4L2_JPEG_REF_HT_AC_LEN] = { + 0x00, 0x02, 0x01, 0x03, 0x03, 0x02, 0x04, 0x03, 0x05, 0x05, 0x04, 0x04, + 0x00, 0x00, 0x01, 0x7D, 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12, + 0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07, 0x22, 0x71, 0x14, 0x32, + 0x81, 0x91, 0xA1, 0x08, 0x23, 0x42, 0xB1, 0xC1, 0x15, 0x52, 0xD1, 0xF0, + 0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0A, 0x16, 0x17, 0x18, 0x19, 0x1A, + 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, + 0x3A, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x53, 0x54, 0x55, + 0x56, 0x57, 0x58, 0x59, 0x5A, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, + 0x6A, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x83, 0x84, 0x85, + 0x86, 0x87, 0x88, 0x89, 0x8A, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, + 0x99, 0x9A, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xB2, + 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xC2, 0xC3, 0xC4, 0xC5, + 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, + 0xD9, 0xDA, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, + 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA +}; +EXPORT_SYMBOL_GPL(v4l2_jpeg_ref_table_luma_ac_ht); + +/* + * Contains the data that needs to be sent in the marker segment of an interchange format JPEG + * stream or an abbreviated format table specification data stream. + * Specifies the huffman table used for encoding the chrominance DC coefficient differences. + * The table represents Table K.4 of ITU-T.81 + */ +const u8 v4l2_jpeg_ref_table_chroma_dc_ht[V4L2_JPEG_REF_HT_DC_LEN] = { + 0x00, 0x03, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, + 0x01, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B +}; +EXPORT_SYMBOL_GPL(v4l2_jpeg_ref_table_chroma_dc_ht); + +/* + * Contains the data that needs to be sent in the marker segment of an + * interchange format JPEG stream or an abbreviated format table specification + * data stream. Specifies the huffman table used for encoding the chrominance + * AC coefficients. The table represents Table K.6 of ITU-T.81 + */ +const u8 v4l2_jpeg_ref_table_chroma_ac_ht[V4L2_JPEG_REF_HT_AC_LEN] = { + 0x00, 0x02, 0x01, 0x02, 0x04, 0x04, 0x03, 0x04, 0x07, 0x05, 0x04, 0x04, + 0x00, 0x01, 0x02, 0x77, 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21, + 0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71, 0x13, 0x22, 0x32, 0x81, + 0x08, 0x14, 0x42, 0x91, 0xA1, 0xB1, 0xC1, 0x09, 0x23, 0x33, 0x52, 0xF0, + 0x15, 0x62, 0x72, 0xD1, 0x0A, 0x16, 0x24, 0x34, 0xE1, 0x25, 0xF1, 0x17, + 0x18, 0x19, 0x1A, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x35, 0x36, 0x37, 0x38, + 0x39, 0x3A, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x53, 0x54, + 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, + 0x69, 0x6A, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x82, 0x83, + 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x92, 0x93, 0x94, 0x95, 0x96, + 0x97, 0x98, 0x99, 0x9A, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, + 0xAA, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xC2, 0xC3, + 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, + 0xD7, 0xD8, 0xD9, 0xDA, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, + 0xEA, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA +}; +EXPORT_SYMBOL_GPL(v4l2_jpeg_ref_table_chroma_ac_ht); + +/** + * struct jpeg_stream - JPEG byte stream + * @curr: current position in stream + * @end: end position, after last byte + */ +struct jpeg_stream { + u8 *curr; + u8 *end; +}; + +/* returns a value that fits into u8, or negative error */ +static int jpeg_get_byte(struct jpeg_stream *stream) +{ + if (stream->curr >= stream->end) + return -EINVAL; + + return *stream->curr++; +} + +/* returns a value that fits into u16, or negative error */ +static int jpeg_get_word_be(struct jpeg_stream *stream) +{ + u16 word; + + if (stream->curr + sizeof(__be16) > stream->end) + return -EINVAL; + + word = get_unaligned_be16(stream->curr); + stream->curr += sizeof(__be16); + + return word; +} + +static int jpeg_skip(struct jpeg_stream *stream, size_t len) +{ + if (stream->curr + len > stream->end) + return -EINVAL; + + stream->curr += len; + + return 0; +} + +static int jpeg_next_marker(struct jpeg_stream *stream) +{ + int byte; + u16 marker = 0; + + while ((byte = jpeg_get_byte(stream)) >= 0) { + marker = (marker << 8) | byte; + /* skip stuffing bytes and REServed markers */ + if (marker == TEM || (marker > 0xffbf && marker < 0xffff)) + return marker; + } + + return byte; +} + +/* this does not advance the current position in the stream */ +static int jpeg_reference_segment(struct jpeg_stream *stream, + struct v4l2_jpeg_reference *segment) +{ + u16 len; + + if (stream->curr + sizeof(__be16) > stream->end) + return -EINVAL; + + len = get_unaligned_be16(stream->curr); + if (stream->curr + len > stream->end) + return -EINVAL; + + segment->start = stream->curr; + segment->length = len; + + return 0; +} + +static int v4l2_jpeg_decode_subsampling(u8 nf, u8 h_v) +{ + if (nf == 1) + return V4L2_JPEG_CHROMA_SUBSAMPLING_GRAY; + + /* no chroma subsampling for 4-component images */ + if (nf == 4 && h_v != 0x11) + return -EINVAL; + + switch (h_v) { + case 0x11: + return V4L2_JPEG_CHROMA_SUBSAMPLING_444; + case 0x21: + return V4L2_JPEG_CHROMA_SUBSAMPLING_422; + case 0x22: + return V4L2_JPEG_CHROMA_SUBSAMPLING_420; + case 0x41: + return V4L2_JPEG_CHROMA_SUBSAMPLING_411; + default: + return -EINVAL; + } +} + +static int jpeg_parse_frame_header(struct jpeg_stream *stream, u16 sof_marker, + struct v4l2_jpeg_frame_header *frame_header) +{ + int len = jpeg_get_word_be(stream); + + if (len < 0) + return len; + /* Lf = 8 + 3 * Nf, Nf >= 1 */ + if (len < 8 + 3) + return -EINVAL; + + if (frame_header) { + /* Table B.2 - Frame header parameter sizes and values */ + int p, y, x, nf; + int i; + + p = jpeg_get_byte(stream); + if (p < 0) + return p; + /* + * Baseline DCT only supports 8-bit precision. + * Extended sequential DCT also supports 12-bit precision. + */ + if (p != 8 && (p != 12 || sof_marker != SOF1)) + return -EINVAL; + + y = jpeg_get_word_be(stream); + if (y < 0) + return y; + if (y == 0) + return -EINVAL; + + x = jpeg_get_word_be(stream); + if (x < 0) + return x; + if (x == 0) + return -EINVAL; + + nf = jpeg_get_byte(stream); + if (nf < 0) + return nf; + /* + * The spec allows 1 <= Nf <= 255, but we only support up to 4 + * components. + */ + if (nf < 1 || nf > V4L2_JPEG_MAX_COMPONENTS) + return -EINVAL; + if (len != 8 + 3 * nf) + return -EINVAL; + + frame_header->precision = p; + frame_header->height = y; + frame_header->width = x; + frame_header->num_components = nf; + + for (i = 0; i < nf; i++) { + struct v4l2_jpeg_frame_component_spec *component; + int c, h_v, tq; + + c = jpeg_get_byte(stream); + if (c < 0) + return c; + + h_v = jpeg_get_byte(stream); + if (h_v < 0) + return h_v; + if (i == 0) { + int subs; + + subs = v4l2_jpeg_decode_subsampling(nf, h_v); + if (subs < 0) + return subs; + frame_header->subsampling = subs; + } else if (h_v != 0x11) { + /* all chroma sampling factors must be 1 */ + return -EINVAL; + } + + tq = jpeg_get_byte(stream); + if (tq < 0) + return tq; + + component = &frame_header->component[i]; + component->component_identifier = c; + component->horizontal_sampling_factor = + (h_v >> 4) & 0xf; + component->vertical_sampling_factor = h_v & 0xf; + component->quantization_table_selector = tq; + } + } else { + return jpeg_skip(stream, len - 2); + } + + return 0; +} + +static int jpeg_parse_scan_header(struct jpeg_stream *stream, + struct v4l2_jpeg_scan_header *scan_header) +{ + size_t skip; + int len = jpeg_get_word_be(stream); + + if (len < 0) + return len; + /* Ls = 8 + 3 * Ns, Ns >= 1 */ + if (len < 6 + 2) + return -EINVAL; + + if (scan_header) { + int ns; + int i; + + ns = jpeg_get_byte(stream); + if (ns < 0) + return ns; + if (ns < 1 || ns > 4 || len != 6 + 2 * ns) + return -EINVAL; + + scan_header->num_components = ns; + + for (i = 0; i < ns; i++) { + struct v4l2_jpeg_scan_component_spec *component; + int cs, td_ta; + + cs = jpeg_get_byte(stream); + if (cs < 0) + return cs; + + td_ta = jpeg_get_byte(stream); + if (td_ta < 0) + return td_ta; + + component = &scan_header->component[i]; + component->component_selector = cs; + component->dc_entropy_coding_table_selector = + (td_ta >> 4) & 0xf; + component->ac_entropy_coding_table_selector = + td_ta & 0xf; + } + + skip = 3; /* skip Ss, Se, Ah, and Al */ + } else { + skip = len - 2; + } + + return jpeg_skip(stream, skip); +} + +/* B.2.4.1 Quantization table-specification syntax */ +static int jpeg_parse_quantization_tables(struct jpeg_stream *stream, + u8 precision, + struct v4l2_jpeg_reference *tables) +{ + int len = jpeg_get_word_be(stream); + + if (len < 0) + return len; + /* Lq = 2 + n * 65 (for baseline DCT), n >= 1 */ + if (len < 2 + 65) + return -EINVAL; + + len -= 2; + while (len >= 65) { + u8 pq, tq, *qk; + int ret; + int pq_tq = jpeg_get_byte(stream); + + if (pq_tq < 0) + return pq_tq; + + /* quantization table element precision */ + pq = (pq_tq >> 4) & 0xf; + /* + * Only 8-bit Qk values for 8-bit sample precision. Extended + * sequential DCT with 12-bit sample precision also supports + * 16-bit Qk values. + */ + if (pq != 0 && (pq != 1 || precision != 12)) + return -EINVAL; + + /* quantization table destination identifier */ + tq = pq_tq & 0xf; + if (tq > 3) + return -EINVAL; + + /* quantization table element */ + qk = stream->curr; + ret = jpeg_skip(stream, pq ? 128 : 64); + if (ret < 0) + return -EINVAL; + + if (tables) { + tables[tq].start = qk; + tables[tq].length = pq ? 128 : 64; + } + + len -= pq ? 129 : 65; + } + + return 0; +} + +/* B.2.4.2 Huffman table-specification syntax */ +static int jpeg_parse_huffman_tables(struct jpeg_stream *stream, + struct v4l2_jpeg_reference *tables) +{ + int mt; + int len = jpeg_get_word_be(stream); + + if (len < 0) + return len; + /* Table B.5 - Huffman table specification parameter sizes and values */ + if (len < 2 + 17) + return -EINVAL; + + for (len -= 2; len >= 17; len -= 17 + mt) { + u8 tc, th, *table; + int tc_th = jpeg_get_byte(stream); + int i, ret; + + if (tc_th < 0) + return tc_th; + + /* table class - 0 = DC, 1 = AC */ + tc = (tc_th >> 4) & 0xf; + if (tc > 1) + return -EINVAL; + + /* huffman table destination identifier */ + th = tc_th & 0xf; + /* only two Huffman tables for baseline DCT */ + if (th > 1) + return -EINVAL; + + /* BITS - number of Huffman codes with length i */ + table = stream->curr; + mt = 0; + for (i = 0; i < 16; i++) { + int li; + + li = jpeg_get_byte(stream); + if (li < 0) + return li; + + mt += li; + } + /* HUFFVAL - values associated with each Huffman code */ + ret = jpeg_skip(stream, mt); + if (ret < 0) + return ret; + + if (tables) { + tables[(tc << 1) | th].start = table; + tables[(tc << 1) | th].length = stream->curr - table; + } + } + + return jpeg_skip(stream, len - 2); +} + +/* B.2.4.4 Restart interval definition syntax */ +static int jpeg_parse_restart_interval(struct jpeg_stream *stream, + u16 *restart_interval) +{ + int len = jpeg_get_word_be(stream); + int ri; + + if (len < 0) + return len; + if (len != 4) + return -EINVAL; + + ri = jpeg_get_word_be(stream); + if (ri < 0) + return ri; + + *restart_interval = ri; + + return 0; +} + +static int jpeg_skip_segment(struct jpeg_stream *stream) +{ + int len = jpeg_get_word_be(stream); + + if (len < 0) + return len; + if (len < 2) + return -EINVAL; + + return jpeg_skip(stream, len - 2); +} + +/* Rec. ITU-T T.872 (06/2012) 6.5.3 */ +static int jpeg_parse_app14_data(struct jpeg_stream *stream, + enum v4l2_jpeg_app14_tf *tf) +{ + int ret; + int lp; + int skip; + + lp = jpeg_get_word_be(stream); + if (lp < 0) + return lp; + + /* Check for "Adobe\0" in Ap1..6 */ + if (stream->curr + 6 > stream->end || + strncmp(stream->curr, "Adobe\0", 6)) + return jpeg_skip(stream, lp - 2); + + /* get to Ap12 */ + ret = jpeg_skip(stream, 11); + if (ret < 0) + return ret; + + ret = jpeg_get_byte(stream); + if (ret < 0) + return ret; + + *tf = ret; + + /* skip the rest of the segment, this ensures at least it is complete */ + skip = lp - 2 - 11 - 1; + return jpeg_skip(stream, skip); +} + +/** + * v4l2_jpeg_parse_header - locate marker segments and optionally parse headers + * @buf: address of the JPEG buffer, should start with a SOI marker + * @len: length of the JPEG buffer + * @out: returns marker segment positions and optionally parsed headers + * + * The out->scan_header pointer must be initialized to NULL or point to a valid + * v4l2_jpeg_scan_header structure. The out->huffman_tables and + * out->quantization_tables pointers must be initialized to NULL or point to a + * valid array of 4 v4l2_jpeg_reference structures each. + * + * Returns 0 or negative error if parsing failed. + */ +int v4l2_jpeg_parse_header(void *buf, size_t len, struct v4l2_jpeg_header *out) +{ + struct jpeg_stream stream; + int marker; + int ret = 0; + + stream.curr = buf; + stream.end = stream.curr + len; + + out->num_dht = 0; + out->num_dqt = 0; + + /* the first bytes must be SOI, B.2.1 High-level syntax */ + if (jpeg_get_word_be(&stream) != SOI) + return -EINVAL; + + /* init value to signal if this marker is not present */ + out->app14_tf = V4L2_JPEG_APP14_TF_UNKNOWN; + + /* loop through marker segments */ + while ((marker = jpeg_next_marker(&stream)) >= 0) { + switch (marker) { + /* baseline DCT, extended sequential DCT */ + case SOF0 ... SOF1: + ret = jpeg_reference_segment(&stream, &out->sof); + if (ret < 0) + return ret; + ret = jpeg_parse_frame_header(&stream, marker, + &out->frame); + break; + /* progressive, lossless */ + case SOF2 ... SOF3: + /* differential coding */ + case SOF5 ... SOF7: + /* arithmetic coding */ + case SOF9 ... SOF11: + case SOF13 ... SOF15: + case DAC: + case TEM: + return -EINVAL; + + case DHT: + ret = jpeg_reference_segment(&stream, + &out->dht[out->num_dht++ % 4]); + if (ret < 0) + return ret; + if (!out->huffman_tables) { + ret = jpeg_skip_segment(&stream); + break; + } + ret = jpeg_parse_huffman_tables(&stream, + out->huffman_tables); + break; + case DQT: + ret = jpeg_reference_segment(&stream, + &out->dqt[out->num_dqt++ % 4]); + if (ret < 0) + return ret; + if (!out->quantization_tables) { + ret = jpeg_skip_segment(&stream); + break; + } + ret = jpeg_parse_quantization_tables(&stream, + out->frame.precision, + out->quantization_tables); + break; + case DRI: + ret = jpeg_parse_restart_interval(&stream, + &out->restart_interval); + break; + case APP14: + ret = jpeg_parse_app14_data(&stream, + &out->app14_tf); + break; + case SOS: + ret = jpeg_reference_segment(&stream, &out->sos); + if (ret < 0) + return ret; + ret = jpeg_parse_scan_header(&stream, out->scan); + /* + * stop parsing, the scan header marks the beginning of + * the entropy coded segment + */ + out->ecs_offset = stream.curr - (u8 *)buf; + return ret; + + /* markers without parameters */ + case RST0 ... RST7: /* restart */ + case SOI: /* start of image */ + case EOI: /* end of image */ + break; + + /* skip unknown or unsupported marker segments */ + default: + ret = jpeg_skip_segment(&stream); + break; + } + if (ret < 0) + return ret; + } + + return marker; +} +EXPORT_SYMBOL_GPL(v4l2_jpeg_parse_header); |